From an email posted to Baen's Bar Honorverse dated June 1, 2005:

Heavy attack craft (HAC)

    There's no point in flogging this particular deceased equine. I cannot conceive of any tactical or operational circumstances under which it would make sense to invest funds and yard capacity in a so-called "heavy attack craft." Either build LACs, or else build hyper-capable units; don't waste your industrial resources and manpower on building and crewing hybrids which will lack the flexibility of either. I can't speak for every theorist out there, but I can say that neither the Manticoran Alliance nor the Republic of Haven is going to be investing in "HAC." This is another example of the "specialist" design theory which both the Manties and the Havenites have rejected. While both sides have built occasional specialized units -- the Havenite Cimeterre-class LAC, for example, is actually a more "specialized unit" than the Shrike or Ferret, if you want to look at it that way -- they will do so only if there is no other way to get the capability they require. Like every real world naval designer, they want the maximum possible capability in each unit they build. They accept restricted capabilities only when forced to do so by physical limitations or fiscal constraints, neither of which apply in the case of the "HAC." The so-called "heavy attack craft" proposals I've seen (and I'll admit, I stopped looking at them quite some time ago) are all solutions looking for problems. I've yet to see any suggested employment for them which couldn't be accomplished equally well by an equivalent tonnage of light attack craft, or by hyper-capable units which could also be employed independently in interstellar operations of their own.