I beat scout teams with my subs all the time. Yet I'm not sure of 100%wins when I face 4.5* quality teams with my scout team. I got 4 7* as well but it don't mean nothing. I say 10 quality and up is most likely almost impossible( almost). 5 quality? Your opponent is also worried.
Lost 2-1
I dont know how he plays he used 5-6 difference format through the CL