That's what's so strange. You see Klingon ships destroying Jem Hadar ships, Cardassian doing it, but never a Starfleet vessel, except for the Defiant, a Defiant type vessel, and maybe a Runabout.
And even then with the Runabout, the Bug ship's vulnerable point was given to Odo, otherwise they would have been destroyed.
At most you'll see a Starfleet ship firing on a Dominion ship, but not destroying it, not in all 4 seasons we've seen the Domonion. Whether they show it or not might not mean anything, but it does give it an odd feel to the whole concept.