I am trying to get marines to follow me and I used this

(script startup ai_enhancement
(ai_follow_target_players Marine_followers)
)

and I made the multiple squads with their fire positions being a, b, and c and I have migrate on and they won't follow me whats the problem here anyone?

Following can be tricky at first. I recently had issues with having my own allies follow, but my last test had them follow pretty well. Basically, when you Spawn your encounter, spawn the encounter by squads. This means by using the (ai_place encounter/squad) script. At least, this is what I did and my Allies ended up being following their spots pretty well.

You also will want to make sure they Automatically Migrate or that you use the (ai_migrate) script to ensure they do move, however, the automatic migration is definitely the best way without a scripted feel to it. You'll find the automatic migration check box where the AI Encounter is in Guerilla or Sapien.