Ahh sorry to hear that. All the dudes will always try to stay close to you. "defend" mode dudes have a very short action radius, meaning they will always stay right by your side while "charge"-mode dudes are a bit more eager to fight, meaning they run further distances from you. But they too will return to you if you are too far away. If you feel like they are getting overrun, pull them away from the enemies by running away. Level 1 relies heavily on the "charge" mode dudes, as they do pack quite a punch, but they are pretty fragile. The healer is the round dude that spawns after wave 1. They always stay with you and if you lead them to wounded ally dudes, they will heal them.
I hope that helps!