Besides lore theories on the age of the two fighters (wich we DON’T know), we should only judge the results on two factors, the skills shown in the movies, and the weapons they got:
on the weapons matter, City is far superior, but even if we put them on the same ground with the same weaponry… City fought entire groups of armed criminals, policemen, and even survived and defeated a team of people ready to ambush him (and wich knew exactly his weaknesses)
yes, Jungle defeated a team of 7 trained soldiers, toying with them and (rightly) using plasma every time it was needed, but that was in my opinion a fair smaller challenge compared to what City did.
Sadly City was defeated by Harrigan, but as already said he faced a lot of stuff, and Harrigan just used the chances he got; even in their final fight, with 8 bulletholes in the body and without an arm, City had him on his knees.
City Hunter wins, both for weapons and for skills.
I never understood the veneration for Jungle, he’s super cool yeah, but he did “standard Predator performance”, wich of course it’s good (and better for example than the Supers in Predators 2010), but nothing god-like.

