Onoki wins he uses waited boulder to make the raikage heavy and then uses particle style to dismantle Ay. As proof from the madara fight onoki doesn't have to touch you to use weighted boulder, onoki is very underrated it's simply because people love to ride that uchiha/senju stick.
Can Oonoki hit Raikage with Jinton before Raikage lands a full power Lariat to the Old Man's chest? Nahhh.
- Raikage too fast and strong for Oonoki to hit, or defend against. Raikage takes this Mid Difficulty.
raikage has bijuu level chakra, generally lightning over earth, and he is just too fast. Oonoki has to touch something to change its weight. Oonoki can fly raikage can teleport. Oonoki is a beast but I think this is a bad matchup for him.
I think the Gokage rank like this
Onoki
Aye/Tsunade
Mei/Gaara
This ranking is based on general skill as a ninja. It was obvious from the madara fight who fared the best and who fared the worst.
Additionally onoki has his particle style and his ability to fly. So i think based on how he is presented as well as his feats he could and should be the stronger of the 2.