Great, now some people can settle their 2nd city without garrison, while others who have land that merits settling it a little further away have to defend it arbitrarily....
Just so you know we play with balanced maps where the landmass is identical in each starting position.
Either way, this "problem" has not been an issue yet and probably never will be. I can't imagine how setttling close to the enemy is beneficial? The two teams are close together and would surely be able to bunker up and overcome that "rogue" city sooner or later, if by nothing other than sheer numbers (one player cannot defend against two players). If both players settle towards the eastern "flank" then they weaken themselves/set them selves up for failure versus the team on in the West.