Seeing as he played the entirety of the 5 kage + his summoner for fools, I doubt anyone could stand up to him even before he got Rinnegan and when he was mortal. He could've also aimed at getting Kyuubi, and that'd be overkill.
With Infinite chakra, an immortal body, Mokuton Jutsus and the Rin'negan.
All of the above he hasn't in the post battle against Hashirama, meaning the only game breaker he would have would be Perfect Susano'o ( since Niidaime Hokage would counter easily his Katons ), which can't be used forever most likely and still would be manageable if Mito had any form of control over Kyuubi's powers and chakra.
There are too much unknown over that era, so let's not be too hasty to judge
Originally Posted by Fox666
I think he was said to have been the greatest of the Kages so far, which can be refering to his administration.
Probably only Niidaime Hokage made more mistakes that Hiruzen, which was nothing more than a weak-willed puppet.
Hiruzen reign as a Hokage was, pardon my language, absolute and utter shit.
I made a thread about it somewhere, will probably copy/paste it there
Well considering how powerful Madara was, it surprises me a bit that Nidaime Hokage didn't try to Edo Tensei him. I am assuming he ETed a few ninja before banning it. Madara would have figured high on that list. If they had done it they would have been in for a rude shock