there is a thread that explains the operation of the ballast tanks in the real Type VII and why it was simplified for the game.
https://www.subsim.com/radioroom/sho...d.php?t=227325
Basically, a real Uboat had a crew of 40+ while Wolfpack can only have 7 players max, so the operation was simplified. Wolfpack still has the most complex/complete dive operation mechanism of any available subsim.