can we add a third follower turtle using tf? what additional steps are required for column formation?

edit

I have done ros tutorial on follower leader until dynamic transform. I need to add a third follower turtle using tf. The leader is gonna start from centre without rotation and followers should start from a random position. firstly leader should call them in column formation having one follower 1m behin leader and second behind 1st and 1m apart. then leader starts movement and when leader hits wall obviously followers hit wall. leader call them back to initial positions.