Twigs, while I mostly agree with you that HV are worthless as an alliance unit, I find them invaluable on attacking. Sure, I could be more careful with what targets I pick and stop attacking in my 90%+ range, but seeing as how I like to play that way, HVs are invaluable. I can pretty much hit any target (excluding Sorcs, those always rape).
I generally play 3 guru : 2 pom : 1.5 hv : 2m total nv, and usually do quite well. Having flak is more important than loading up on these troops though. As a pom, I try to stay about 35% land fat. Never really had an issue with it, tbh.
Also, I've been messing around a bit, rushing Arsos with 10m Hip, 15m guru and 8m HV... 43m Arso stop everything but 1.8m HV. HV might not be hugely effective at stopping stuff, but they certainly give you a better chance of not having all your troops mullered by bloody Arsos.