i would have said airborne and defensive since that is the only doctrines where i haven't found a great working company build for me (except 3 AB snipers but thats a different story)
but since we are not allowed to say airborne i would say defensive (but probably because that suck ass campy shit gameplay with flaks don't fit to my style)
if we consider the changelog of the patch that isn't released yet (since 10 days
) i would say terror will be the weakest..(at least the pre rework nerfed old doctrine abilities)
it had only one good build and that will get nerfed to hell
and tankhunter...because after the nerf of stummel and some other stuff
(in changelog were no exact stats but i bet it will be nerfed to being useless) they have no good stuff
and people wo say the hetzer is best allround tank go onl. and i roflstomp you
don't know why people complain about blitz i had 2 decent blitz company builds
In fact, Blitzkreig doesn't make sense to me at all, it is supposed to be built around fast, harrassing attacks against the opponent anywhere, but only Lightning War allows you to do this to any effect, but that's now been nerfed, and it still gimps your infantry for 60 seconds.
maybe you should think about blitz more in kind of a low support weapons and more tanks supported by infantry company
only fail for blitz is that p4s are shit currently in eir