Hiruzen has been hyped as the strongest of the 5 kages of his gen and the strongest overall Hokages
by powerscaling that makes him stronger than madara. and can you see hiruzen doing ANYTHING to madara? or third raikage? that hype is worthless. it was never mentioned again and was in part 1, no less.
Feat wise old Hiruzen took on Oro, Edo Hashi and Edo Tobirama ON HIS OWN unlike old Oonoki who had the help of four other kages against Edo Madara.
he didnt take on edo tobirama. he blocked one jutsu and for the rest of the fight, tobirama did zilch. orochimaru for 90% of the match, did nothing except blocking enma twice and using his kusanagi to stab hiruzen in the back. hiruzen ended up having to kill himself, knowing oro and kages were toying around with him. granted onoki would have lost but he has no sealing techniques so of course.
Hiruzen could go underground or use bunshin feints to counter jinton
underground...against a master of doton with many years of experience ahead of hiruzen...
and onoki is well aware of clones as he uses them himself regularly
Hiruzen apparently was a master illusionist which would allow him to trap Oonoki in a genjutsu
ebisus word is essentially worthless. he could have been talking about previous kages anyways