From what the Manga has shown us, we can accurately conclude that Both the Third and Fourth Raikage are the strongest Kages. We can't accurately judge minato yet, we know he strong, but how strong?
You cannot accurately conclude which Kage is stronger when we are dealing with a group of very powerful shinobi. You can give your opinion..but if I say Onooki is stronger than Muu, you cannot say I'm wrong because this cannot be accurately concluded.
"From what the Manga has shown us" , this is why people believe the Byakugan is useless or why people think that Tsunade is worthless (Just examples) when in reality they are not. People underrate certain characters and abilities because the manga does not clearly "show us" or "tells us" (in some cases people don't know how to read but whatever) that these techniques or shinobi are in fact useful and strong. You base your "accurate" conclusions on what the manga "literally" says or shows..you have to analyze things a bit more. People like you are easily persuaded, if in the next manga chapter, Kabutamoru is shown saying "Sakura is the strongest shinobi" you'd probably back it up along with all her fanboys because the manga "has shown" us. You need to base your conclusions on aspects other than "oh Itachi has a big guy behind him", "oh this character said this thing so it must be true" or "oh this jutsu is so action-packed and nobody has countered it".
Finally, to answer your thread, I think the strongest Kages are:
1) Hiruzen Sarutobi
2) Third Raikage
3) Minato
4) Onoki
5) Muu
Now, If I were to make a team of Kages to
work together, I'd add Tsunade.
