Capital ships and raiding defenses
I'm sorry, but there still seem to be some misconceptions running around on this topic.
First, smaller ships cannot move faster, whether in normal-space or in hyper-space, then larger ships. They can accelerate faster, which means that they can reach their maximum normal-space velocity more rapidly, but they are limited to the same maximum velocity. That applies not only to starships, but also to LACs.
Second, smaller ships cannot move higher in the hyper bands than larger vessels. Dispatch boats fairly routinely do use higher bands -- in particular, the highest presently obtainable bands -- than regular warships do, and warships regularly use higher hyper bands than merchantships do. However, the reason dispatch boats use higher bands is that given the current state of hyper generator technology, the chances of a catastrophic malfunction at this higher bands, while relatively low, is still much higher than in the lower bands. This means that there is a measurably greater risk of the ship being destroyed if it uses those higher bands, and people are more willing to risk that possibility with a dispatch boat with a crew of under 50 than they are with a superdreadnought with a crew measured in the thousands. There's also the relative differential in industrial effort and combat power represented by the two vessels when it comes to deciding whether or not to risk their destruction for a marginally shorter passage time.
In reference to the second paragraph above, in Honor of the Queen, Alice Truman takes her light cruiser to exactly the same hyper bands that a dispatch boat would have traveled through. In fact, she takes her ship right to the very limit its hyper generator technology would permit and almost loses the ship as a consequence, as she explains to Hamish Alexander later.
In short, there is no strategic speed advantage for smaller vessels as compared to larger vessels, except in as much as one might be more willing to risk losing the smaller vessel by pushing its luck. The problem with this analogy in Torch's case is that each of the battlecruiser-sized units you seem to be promoting would represent the equivalent of an entire task force for a navy the size of the Star Kingdom's even before the First Havenite War.
The task group you are projecting also could not "hit all but the nastiest of defenses." They could rip the crap out of most independent Verge systems, because most of them are far too poverty-stricken to maintain anything much stronger than perhaps a midway point between Nuncio's handful of LACs and the Graysons' pre-alliance navy, and their technology is going to be much less capable than that of the attackers. Almost any Solarian system-defense force could deal with your projected attack group unless the attack group had multidrive missiles, and it is extraordinarily unlikely either Haven or Manticore will be providing them for offensive use. Neither the Republic nor the Star Kingdom (excuse me, Star Empire) is going to want to risk that sort of technology falling into the hands of a Manpower stooge aboard a disabled friendly vessel, especially not after what Technodyne tried to pull in the Battle of Monica. Assuming, however, that you had Agamemnons, you still wouldn't have the onboard firepower to take on most moderately defended targets. You'd need a lot more than four of them to deal with the degree of missile defense that can be generated in any near-planet defensive scenario, if only because of the limits on your onboard ammunition supply. You'd probably get away with a few painful raids on Manpower-related targets in the Verge, but only until they decided to start beefing up their own defenses (which is precisely the motive of the smaller, cheaper, far more affordable, far more affordable, and far more easily manned is that I sketched out earlier). As far as Manpower-related targets in the Shell, or in the Old League are concerned, hang it up. By the time you managed to penetrate that deeply you'd probably be up against first-line or second-line or Solarian defensive technology which, while inferior to that of the Alliance for the Republic of Haven at this time, should still be capable of dealing with any [raiding force] someplace the size of Torch could possibly put together. (And, of course, in Torch's case, there's another factor to consider which is that the League is not going to react well to attacks on its sovereign territory, even if those attacks are directed at an outlaw corporation rather than at the League proper. There are things like collateral damage and the violation of sovereignty to consider. And unfortunately for Torch in this regard, the existence of a home world provides a target for Solarian reprisals in the event of such attacks. It wouldn't be a case of the Audubon Ballroom assassinating a few dozen Manpower executives and then vanishing back into the general population of the League. It would be a case of one recognizable nationstate attacking another recognizable nationstate, and the League's response would probably be devastating.)
Getting back to your proposed force mix, however, Torch simply does not have the level of resources required to build and support the types of raiding forces that you're talking about. As such, I can see absolutely no logical reason for them to try and invest in those forces, especially when there are cheaper, more economical, and more sustainable options available for meeting their basic requirements.
Again, this would be a poor investment for a joint defense concept for two stars like Grayson and Masada. Assuming an absolute monopoly on the technology involved (that is, only the defenders have missile pods, pod-layers, LACs as capable as Shrikes, etc.), then this force would probably be able to hold its own against a moderately powerful task force. Against multiple squadrons of superdreadnoughts (and in this case I am defining "multiple" as simply meaning more than one), it would be chipped beef on toast. It simply does not have the sustained the firepower to stop superdreadnoughts. Cruisers, battlecruisers, destroyers, yes; ships of the wall, no.
Given that there is no strategic speed advantage for these units over the bigger and heavier superdreadnoughts, and given that what you are really talking about with LACs is highly capable torpedo boats which would be required to penetrate the range dominated by battleship-sized guns, it would make far more sense to invest the same funds and the same manpower in building even a severely limited number of dreadnoughts or superdreadnoughts. Even a modern battleship design would be superior to your group of battlecruisers and a small CLAC for the defensive needs you've sketched out here. It would be tougher, capable of mounting more weapons (including pods, if you went with a pod design), and exercise far more deterrent value. (It would be analogous to a coast defense battleship: not really designed to fight the all-up capital ships of a first-rank naval power, but powerful enough to pose at least a significant threat to those capital ships in order to make an aggressor think twice, and capable of pounding the crap out of anything smaller than a first-rank battleship.) If you really want to base your system-defense on LACs and missile pods, it would be incredibly less expensive to simply go ahead and build permanent bases for your LACs in each star system, and then to place missile pods in orbit around the targets you want to defend with as close to a Moriarty-style control net as you tech base could provide. You could get far more firepower into place for the same expense, you wouldn't have to worry about whether or not both systems were threatened simultaneously, and you would save the manning penalty of the mobile platforms involved.
The present weapons mix in the Honorverse does not offer superior mobility enough of an offsetting combat edge to neutralize "the power of the gun." There clearly will be instances, probably quite a few of them, in which the acceleration differential will permit lighter forces to avoid action with heavier forces. Once action is joined, however, the lighter units are unlikely to have enough of an acceleration advantage to escape destruction by simply running. Obviously, a huge amount would depend on the geometry of the engagement, and I can think of several situations in which the light units' ability to escape would be higher than others, but somebody building a navy doesn't rely on the "well, sometimes it might work" approach.
What I think many LAC proponents are missing on some sort of emotional level is the point which has been made not just by me but by other commenters. In short, LACs are not strike aircraft and CLACs are not nuclear powered aircraft carriers. If you want a better analogy for the naval paradigm of the Honorverse, it would be fleets of updated Iowa-class battleships armed not with 16-inch guns, but with Mach 3-capable cruise missiles with a range measured in thousands of miles and no strike aircraft. Actually, the superdreadnoughts of the Honorverse would be more like updated Yamatos or Montanas with the same sort of armament and the Nikes would be more like Alaska-class "large" heavy cruisers. Arguably, the Nike and/or Agamemnon might be more equivalent to the Iowa (assuming that you're going to compare the superdreadnoughts to the Montana), since I always thought of the Iowas more as the final iteration of the battlecruiser, especially when you stacked it up against the protection built into the Yamato and the Montana. The reason I went with the Alaska analogy is that neither the Nike nor the Agamemnon has the sustained combat capability of the Iowa (we're speaking in analogy terms here, remember), and both of them are more likely to be armed with the Mark 16 than with the Mark 23 all-up MDM, which makes a better parallel to the Alaska's 12-inch guns than to the Iowa's 16-inch main battery.
At any rate, the point that I'm trying to make here is that LACs do not have sufficient firepower to take out capital ships which know they're coming except under extraordinary conditions. Even then, the LACs need an enormous numerical advantage. They are a good choice for general security duties within star systems where the primary threat will be from something lighter than ships of the wall. They are a good choice for attacking relatively lightly defended targets, but note the caveat -- lightly defended targets. They provide a useful anti-missile screening capability for capital ships using individually hard to target and kill platforms, each of which represents a far smaller personnel loss than using destroyers or cruisers for the same function. They are useful for reconnaissance if you don't have the equivalent of the Manties' Ghost Rider platforms available. They are not, however, and will not be (barring some enormous shift in the weapons technology capabilities of the Honorverse) an effective tool for use against heavy military starships except in such numbers as to require at least as much investment in money, building and maintenance resources and tech base, and manpower as a squadron or so of battleships (with modern technology) or dreadnoughts.
I think that an observation made by a gunnery officer aboard one of the World War I British battlecruisers might bear repeating here. Admiral Fisher had argued that the battlecruisers didn't need armor because "speed was armor." In response to which the wartime gunnery officer commented that grouse were quite speedy, too... but that didn't prevent a good wing shot from filling his bag during the season. Speed and mobility are very, very useful things to have, but they aren't a big enough advantage in the Honorverse to stand in for toughness and protected and sustainable firepower.