Hate to be the dick about it, but there is a reason to let one of them through... that's having higher uptime of damage from that one person you have running over to the other engineer NOT having them spend that time wasted running and killing a target you don't even have to.
Who cares that the star does damage, position properly and you're fine. It's not like there's a lot of healing going out other than to the tank in phase 1.