Just reporting what happened on a 3v3 match just now (won't express opinions, just saying the facts):
I was the gunner on a mino sniping spire with an average-to-good captain. We were against 3 close range ships (goldfish, junker, pyramidion) all with average leveled captains (~lv.20). On our side one captain didn't play at all (running in circles, drunk people you know).
With only greased loaded I missed (hit nothing) just 4 shots (I'm a bad gunner, just saying).
I could manage to put on idle (at quite far range, with greased ammo) 2-3 ships just hitting them once and skipping to the next one. rinse and repeat, while my crewmates were sniping them down.
A sniping spire could completely disable and snipe to death at least 2v1 without getting hit once, with a bad gunner such I am.
-EDIT-
On a 4v4 my gun were disabled twice and that stopped abruptly the perma-control thing. Just because minotaur cannot turn spires, gallions on the other end were are complete joke xD.