yyh but unlike them Law acc woud hv stood a much better chance of winning than themThen by your logic Nami should have been the one to beat Arlong and Chopper should have beaten Wapol and Vivi should have been the one to beat Crocodile and so on.
Luffy was always going to be the one that beat Doflamingo. Especially after what Oda had Zoro do and awesome he was. But I highly doubt the fight is actually over so who knows something weird could happen.