Naruto - Hashirama - Minato - Tobirama/Hiruzen - Tsunade - Kakashi
Naruto - hands down the winner. he reacted to, blocked and swapped hands with fused Momoshiki in base form. and even after taking some serious hits he stood up perfectly fine. once he used SPSM he easily overpowered Fused Momoshiki. If anything i would say in base SM Naruto could still give a hell of a fight to fused Momoshiki and win. after all it was his base Rasengan (that he didnt use because the plot required Boruto to be the hero from this point on) that finished fused Momoshiki. and this was after he went through the extraction process which has to have taken a toll on his body. and fused momoshihki is arguably around Juubidara level or above. and in the war we saw that other Hokage were clearly ouclassed by incomplete Juubito. So this should be without a doubt in his favour.
Hashirama is a no brainer. the man has raw power. SM. and versatality.
I think Minato ranks third. he can more or less triumph over Tobirama in all departments apart from raw power. but the fact that he managed SM means he has to have a good amount of raw power on his side to. he ranks over Hiruzen because twice in the manga Hiruzen spoke highly of Minato, of how only he could defeat Orochimaru when he was first introduced, and how Hiruzen feared the third coffin of Minato to be resurrected.
the fourth position is a bit of mix bag.
on one hand there is Hiruzen's verstality and on other hand comes Tobirama's speed and FTG. this is a good versus with no clear winner for me.
Tsunade ranks higher simply because Kakashi cannot kill her and she can destroy Kakashi with a simple punch.
Kakashi is unfortunately the bottom one and understandbly so.
until they do something foolish and in the future actually end up making Konohamaru Hokage. that would be hilarious.