Well, maybe they can get Odo or Data (I admit, they are probably unaivailable, but usually, Sith Lords and Jedi are this, too)
Startrek Ships are capable of planetary bombardment - the combined Cardassian/Romulan army completely and utterly destroyed the old home planet of the Founders (I admit, it didn`t explode). Sisko once threatened to destroy a planet using "tricobalt" torpedos or something like that.
The main problem probably is that all three universes have their own rules - Lasers are primitive weapon in Startrek (unable to penetrate even the navigational deflectores of the Enterprise D, as told in one episode), but high-end weapon in Starwars.
Each of the three universes has its own rules for FTL travel, sublight travel, weapons technology and so on.
All these things aside, my bets are still on the side of Starfleet.
Even their biggest ship are extremely fast and maneuverable (Impuls engines allow flying at up to 0.9 c), and all of the ships (even the smallest shuttle) have shields. They use weapon based on Antimatter/Matter Anhilation (Photon & Quantum Torpedos) that can fly at similar speed (torpedos can even be fired at warp speed) as the ships themselves, and their weapons have great ranges. (300.000 km for Phasers and 1.500.000 Km for Torpedos).
But I admit, the Defiant Class ships and Whitestar ships look equal in combat abilities.
I think a fight Starwars units vs. Babylon 5 units might be fairer and be more easier to adjucate, because the combat has the same scale.
Big, slow capital ships and many fast and small fighters.
Starwars has its shields, which might prove as an advantage, but Starfuries seem to be much more maneuverable (well, they use real-life physics, X-Wing & co use cinematic aeriel physic) than similar Starwars units.
I think Babylon 5 starcruisers might have an advantage, because their weapons seem to have higher range and they have more concentrated firepower (I guess it would be little problem to destroy the star destroyers shield generator with the Earthforce Cruisers weapons, without having to rely on starfighters)
Mustrum Ridcully