I think Prime Ray beats Prime Garp.
We only have their old counter parts to go by and Old Rayleigh's hype and portrayal shits on Old Garp's hype and portrayal despite Garp being active and Rayleigh being retired.
You didn’t take L if kaido say no one can defeat him in the world when you have losing record like 7 defeat and 18 capture. It is his ego of villain type.
I think it is like shanks vs kaido , king vs Ben, red hair pirates fight beast pirates. Jack bring his army on zou. Red hairs pirates finish faster and able to reach marineford . That is your speed feat