This "age" and "prime" doesn't make sense:
Both were already more or less past 40, so near little to nothing "youth" growth. And if Oden survived - that is if Oda wanted so, due to plot, because power wise he was going for the kill - he would have be able to repeat same feat and eventually even kill Kaido in others circumstances. But, while he did that alone, with 8 men, and a snitch, and Kaido knowing where and when they'll attack, and Oden losing due to the dirtiest trick, if Alliance do beat kaido it will be due to a raid where they prepared everything and kaido wasn't aware of + And all vs 1 fight + no snitch involved - only in the favor of Luffy's team - + no dirty trick involved against luffy's team, let alone having PTSD due to Oden and beeing mentally weakened due to it. Hell, kaido is already weakened by the 9s.
So their feat of beating him = Oden feat of beeing close to wining wasn't it for the trick.