Because the enemy carrier would be right next to the Tyrant, without it being quite able to completely screen the enemy flagship by the time the volley of 32
heavy long-range turbolasers, 4
heavy long-range ion cannons with the same yield, and also hypervelocity cannons, seven bursts of 88mm rounds alongside fifteen of the same 380mm rounds as before, would reach it, it would be possible that some of the fire directed at the enemy carrier hit the Tyrant instead, even though the reverse was the enemy's hope. Also twenty
high-yield, long-range torpedoes were fired at the carrier's exposed hangar, in hopes of provoking a chain reaction that would take at least one of the fighter's fuel reserves or the ordnance magazines down with it (and maybe even the whole carrier if the explosion is big enough).