Okay, I read the idea somewhere else on the forums but modified it.
Level 60-80 in one server and 81-85 in another.
You choose faction (LS/DS), base planet (Coruscant, Lothal), and target planet.
Phase 1- Purge
Everyone on same Base planet fights against enemy faction. Some facilities are there, like comm base, factory, etc, and capturing them gives you a bonus. Factories allow you to send in vehicles (one per attack) (5 attacks per day) based on your affiliation (eg AAT DS , AT-AP LS, etc.) that deal massive damage. Comm Bases give allies TM removal immunity and 2% TM whenever a unit attacks. Destroying enemy captured facilities debuffs them, so it is a gamble to capture them, as losing the main City Battle means defeat. So if DS destroys LS Comm Base, all LS on planet will lose 5% TM when attacked. So attack these facilities wisely, as not being able to put a good Defense team means your entire faction getting debuffed.
Winning City Battle means 'Purging' planet, granting you a win.
To win City Battle, there will be a headquarter target in the background. Target it by tapping on icon and destroy it.
1...2...3! You're dead!