Warp Drive would be the deciding factor. ST ships can fight while traveling at superluminal velocities, and hitting targets.
SW technology shows no such capacity. Blaster bolts, travelling at less than lightspeed, would be unable to hit starships travelling at warp speed. The starships, however, could make strafing passes against the relatively-immobile Star Destroyers/etc and destroy them practically at will.
In a sense, it would be a lot like the old Soviet Union vs USA conventional military argument. The Soviets went for quantity and used their weapons systems like clubs; the USA went for quality and used their weapons systems like fencing rapiers. Field engagements between US tanks and Russian made tanks used by Iraq revealed that a handful of US tanks could and did engage and destroy a hundred Russian-made tanks in short order. The US targeting systems and weapons were longer ranged and more accurate, and our tanks could shoot with pinpoint accuracy while moving at top speed, making them hard targets.
Similarly, ST ships could fly by Star Destroyers at warp and destroy them at will. Warp drive would be the decisive factor. The only thing hyperdrive would be good for is running away from the battle after Starfleet kicks their assets.
For another example, think about what one well-trained sniper with a modern .308 semi-auto, and a 4wheel ATV for transportation, could do to an entire company of Colonial era infantry armed with smoothbore muskets. He could kill several from a far greater distance than they could respond, then move to a new location faster than they could move, wait and do it again.
SW vs ST would be a lot like that. The Empire's massive resources would simply make for a "target rich environment".
(I can't believe I am talking about this...)