ah yes, Teamwork, notice how there's no U in "team"
They do cooperate as Goldenrivet has already described, usually it's three, with two circling and droppinf DCs while one pings or listens to fix your position, they also switch roles often, with one stopping and another starting to make DC runs
they definitely don't behave as if they were all individual destroyers, that would cause a lot more collision-avoidance behaviour than actually occurs in game
the best way to find out would be to start a career in 1944 and see how long you survive