I don’t think so

Pretender

The words I've seen for that are sheep and followers. I dont use the sheep word cause I personally find it a little rude. It's human nature to follow something unfortunately that can turn out really good or really bad

A wanna be

idk ab that one chief

I don't know any but if you mein someone who does anything the others do just to fit in there is a german word called "mitläufer" i do not know if there is a english word that means the same but i doubt it