To make it fair, keep the rear of the shore bat open. When someone jumps to that position, a few troops man the guns. Kill the troops, and the gunner hits the tower and has to re-up to continue firing.
EDIT: That way, the attackers have to brave the anti-air guns to stop the operator yet it wouldn't be a suicide run.
2nd EDIT: The troops manning the gun should also be doing the Macarena.