I don't stay back to kill all the extra enemies, I just go on and start fighting the next part of the strike by myself and wait for the others, but doing this to force them up is a bit much; if you can do the strike by yourself, feel free to go up, but you shouldn't try to change the way others like to play their strikes. If you can't do it alone, stay with your damn group because you don't deserve to dictate how they do the strike