The thread maker has given Minato Sage Mode. That's overkill in my opinion, as Hiruzen + Minato would probably win without it. People say Tsunade will heal everyone, therefore the Kages will outlast the 2 Hokages. However, people conviently miss out the fact that Minato, the fastest ninja ever, will just seal her up before she, or anyone for that matter, can do anything about it.
Hiruzen is referred to as the God of Shinobi. By hype, he can take on atleast the other 4. If not he can solo (this statement is based on the hype surrounding him!!) I rate Minato very highly (not a fanboy) as his battle strategy is near enough impossible to counter, without posing serious harm to yourself, or increasing the possibility of losing chakra rapidly (Itachi Susanoo, Tsunade healing etc.) Based on Hiruzen's hype, he can near enough solo these Kages. Tbh, I dont even rate these Kages very highly. The only two I think are powerful, relative to previous Kages, are Oniki and Mei (think Mei has a lot more than has been shown), maybe Gaara.