I would agree that outposts should stop just building cities abit more, and meaby city borders too (if the city is placed AFTER the outpost).
But I think this should be considered when we know what kind of cities and outposts we want to keep. Cause right now outposts are just spammable silly wooden structures that allow you to grab resources, they seem abit dull to me to be honest.
But at some point, I hope there is a way besides cities and wars to have the AI keep a little distance.
Given ofcourse that you are rather small compared to them, and they have space etc.
Edit: Spelling
Sincerely
~ Kongdej