Would a Federation warship like the Defiant out gun a Star Wars Star Destroyer? Who has a bigger armada? Who has the tactical advantage? Don’t forget that The Federation includes the Klingons, who love warfare and have fast, agile, heavily armed ships, with cloaking devices, and the Vulcans with superior logic and tactical planning.
There’s a fan fic about exactly this question, written by Graham Kennedy (of the Daystrom Institute Technical Library website.)
https://www.ditl.org/portal-chapter1.php
tl;dr: Federation shields, weapons, engines, and tactics are vastly superior, and they are nearly impervious to the Force. But the Empire has a huge numerical advantage.
spoiler
The Federation wins, but not easily. Mars is destroyed by the Death Star.