There are so many nooks and crannies that it's almost impossible to perfectly spawnbust either way. Going to be a headache to keep track of all the possible barbarian threats when they start running at cities.
If you're ok with sending the warrior far away (in the case of a land bridge) and leaving the area open I'd go ahead and move.
If you're ok with sending the warrior far away (in the case of a land bridge) and leaving the area open I'd go ahead and move.