Hagler was more complete, fought the better opposition, could switch up his style very adeptly. Hagler, hands down.
Funnily enough, my 2 favourite fighters of all time. P4P who wins? tough one, an absolute tear-up over 15 rounds, but I have a sneaky regard for The Rock. Vito but with much greater power. Marciano hits anything he can and I think he could nick this through rounds 13-15.