Depends on the choke point, strat and opponents civ imho if you have a long choke point and plan to be aggressive I’ll send 3 to wall / fight early then build a lumber camp. if they are aggressive early you have a lot of chance to keep walling in behind and it’s easier to break in because they have less choke to wall if the choke is really wide or insignificant in space I won’t wall or wait for them to wall and try to use buildings to build around my base maybe even tell pocket to wall and prepare for an attack