I really think that this will work, for all the Trekies and SW fans.
Some of the ideas that i(with the help of other people) have thought up:
The two sides of each universe would ally into one faction(i.e. Federation+Borg, Imperials+Rebels, and Core+Arm)
Each of the factions would have an uber weapon: ST get a Borg Sphere, TA get an upgraded Krog, and SW get an AT-AT.
And each faction also get secondary items to benefit the rest of the army:
SW get Borg adaptation shields(not as unbalanced as you think), TA get nukes, and SW get Jedi/Sith.
If anyone has any ideas on this, please tell me, im always open to new ideas.

Oh, please, this is not the place to mock any of the factions. i dont want to hear anything like "Star Trek is stupid" or "SW can go jump off a cliff" ect.
Thank you for considering this,
Zoy64