Mechanics of units helping WoL

[JoeyB98]

What the title says. Does anyone know the mechanics of units helping an enemy's war of liberation, and how to avoid it?

 

[Hippo8085]

If they are within the flip zone, they will disappear. No units in flip zone means no flips. If you want to be sure to retain cities you will have to station a lot of units in the cities that will be flipped, including many different types for counter.

If you have a choice, it is easier to raze cities in a flip zone, then resettle them after the flip. Wait to settle areas until the last flip has happened.