Since the Naruto discussions are not ending, I might give my own opinion on it (between Minato and Tobirama). One is the Fourth and the other is the Second. Guess who else are second and fourth. That's right, none other than Zoro and Sanji (courtesy of latest bounties). It's evident that Zoro mid-high diffs Sanji. Hence proven that Tobirama will beat Minato in mid-high diff fight.