Just been reading a book by Anthony Trew about convoying to Russia in 1944.
Book is novel but he commanded destroyers in WWII so I would expect tactics are based on reality.
Convoy assembled in Loch Ewe and as they left they detected a U-boat.
Two destroyers tracked it and setup a 'creeping' attack.
Ship A hunts, Ship B attacks. As follows:
Destroyer A tracks the U-boat, pinging like mad, coming up behind it.
Then Destroyer B comes over and slips in front of Destroyer A (not pinging at any time). Captain of A controls the attack, slows ship A to make U-boat think its slipping away, while ship B runs over the U-boat guided by Ship A's sonar.
When captain of A thinks B is far enough in front of U-boat for DCs to drop right, he orders the DC attack.
result: Destroyers 1 U-boat 0.
Nasty.
Hope GWX developers don't model that!