
submarines are slow
but if they have a ring of spawn points around bases like pt boats do on ozkansas they will have the ability to ambush cv groups and destroy them

in fact if the subs are added like pt boats and use same spawns it would work.
if they were added as a manned vehicle just like a pt boat they would be used extensively to fight against attacking task forces which traveling at 45mph subs couldnt chase, but heck even high speed pt boats cant chase cv groups moving away with any success. pretty much all pt attacks on these fast moving fleets are already ambush attacks.
a simple uboat would need about the same number of crew positions as a ground vehicle.
it would also need 3 depth positions:
surfaced ( deck guns enabled to be manned by player as well as torpedoes)
periscope depth submerged (torpedoes and periscope enabled)
maximum depth submerged evasive depth to escape from uboat hunters etc. would give need for tbm3 and its historical depth charge loadout if the sub could run deep.
well i think that would rock and it would work and get used and not be some dormant cool feature thats nonusable.