A wolf and a penguin could never live together, nor could a camel and a hippopotamus. That would be absurd.
And the older you get, the fewer things you really love. And by the time you get to my age, maybe it's only one or two things. With me, I think it's one.
Do I get that right, that there is nothing you can do against an army of another player hanging around at one of your own cities of the same "side", lingering for an opportunity to start a civil war?
You cannot attack it, because your own army of the same side will coexist with it and your army of the opposite site may not enter your city. And neither you can start a "defensice civil war" in one of your own cities, to get rid off this army, right?
Correct, you cannot attack it with your armies and you cannot start a "defensive civil war".