I thought super subs only increased the attack power.
The tank armor is waaaaaay overpowered.  So if you had 10 tanks, it would take 11 hits to kill 1?  That’s crazy, man, you need to modify that.
Battleships (sounds like you’re talking AAR) cost 24.  Tanks cost 5.
That one’s a bigger game-breaker than 3 dice heavy bombers!