All the other Captains have done a great job but Sisko had to run a war. That puts him over the top.
Sisko didn't run the war. He was a tactical commander who, by merit of his billet, had a bit more say with the admirals in the operational planning of the theatre he was attached to.
Getting the Romulans into the war, and convincing the Prohpets to wave their hand, had nothing to do with his tactical skills.
The only time we see Sisko with, perhaps, major authority over the fleet is in Operation Return. (The rest of those big flashy dumbfests he's either always acting as an advisor to the admirals/generals commanding the fleet or just being a plain old starship captain.) And I can't say Operation Return makes he think: "Hey, he's a much better tactician than s0-and-so..."