I think Benavidez wins by KO. Maybe in the late rounds. Plant can't go 12 rounds at high speed without running out of gas. Plant does well when he can dominate and set his own pace. I don't think he could do that with Benavidez who is so good and fast and who fights hard and fast all fight.
I'd rather see Charlo vs Benevides and Plant vs Canelo, winners face off.
Problem is Benevides no longer has a belt so for Charlo beating him does nothing for him in terms of getting Canelo into the ring with him.
If he would stop being obsessed with Canelo and focus on building his own brand legacy he would he a mega star right now, the fool.