That's actually not a bad match up. Both are in charge of knackered stations which have had some serious fire-power upgrades, and both have large compliments of small craft. Both have Mystical powers, and command of a single super-duper hi-tech escort.
However its gotta be Sheridan for the win. I base this on three things:
1: Sisko has a signed baseball, Sheridan has a kick ass motorcycle.
2: DS9 Orbits wormhole with ancient beings who refuse to help and are the equivalent of space hippies, which come from the wussy end of the galaxy filled with annoying races (Bajorans, Defari, hell even the Cardassians eventually submitted to the Beta Urase field and became wimps). B5 Orbits a plant which has ancient weapons technology that can obliterate anything, and Sheridan has the remote control...
3: By the rules set down by WWWF Grudge match, back when the internet was young and I used a Dial up modem to access it, "Star Trek MUST Lose". Just Ctrl+F that term, which was something else our rudimentary browsers didn't have back in the day.