Thanks. BTW, I like the work you and the other developers did in World in Flames and I have some suggestions:
AI (for Neutral and playerless slots)
Heavy artillery (ex. Kanone 18, Long Tom) (you can upgrade the AT guns to howitzers)
Coastal artillery and AA guns can fire on land (but will become more expensive to avoid people making too much of them)
Snipers
MG squads
Light cruisers (Brooklyn-class, Chapayev-class, Leipzig-class)
Battlecruisers (Repulse, Scharnhorst, Hood)
Other heavy cruiser classes (Admiral Hipper-class, Des Moines-class, Kent-class, Takao-class)