not sure why they changed the 2 trees doctrine selection, which was just more interesting since it gave an additional choice after choosing the doctrine.
What I really see as doctrine conception failure in COH2, is the fact that late game tanks cost fuel which forces you to not spend too much fuel if you want you tiger/85/elephantz/ISU which is boring. Should cost no fuel but come later CP wise IMHO
Nice idea, but it probably wouldn't work in this game. High manpower costs are just ridiculous to wait for, especially in the late game when you have a large army and your manpower income is reduced to well below 200 manpower per minute. The call-ins already require 500+ manpower (KV-8 and P4 Commander excluded) and that's quite a lengthy wait. Adding more manpower to that is not going to help.
Plus, some of the call-ins would just be OP and make other units redundant if they didn't cost any fuel (Tiger with heavy T3 and T/34-85 combo'd with Su-85 comes to mind).
@OP: I hope they'll expand on the doctrines as well, but it's probably on the back-burner for now if anything.