Just as other ships may, submarines may also move out of a sea zone where they begin their turn with enemy ships, even destroyers. The destroyer doesn’t stop the sub’s movement, as the sub didn’t enter the sea zone - it started off there.
We play with four,
hoping to add another. We also speed up the game by going all Axis then all Allies. We are going to add timers, to keep the game moving, we include a 6.5 hour time limit on our games, with pizza and beer, or in my case a shot of whiskey can not be with held.
I found that sending men in the baltic sea in AAE was a faster way to send troops out to the front which it did also i some how took leningrad on 1st turn and he was pissed because men in russia and belorussia had a choice and they had to retreat and keep a few men there. So making a bit of a navy for germany can be profitable if the russian rolls are “5’s”