Chris has RE1 and CV which beats out RE2 in terms of kill count.
RE5 vs RE4..... granted Leon would have credit for like 95% of kills in 4 while Chris would only get credit for half the kills in 5, but 5 has a lot more enemies than 4 does to the point where I can easily believe that 5 has twice as much if not more majini than RE4 has Ganado.
RE6 both characters probably deal with and kill a similar amount of enemies.
If you look at the plot outsjde the games, Chris is constantly travelling to deal with global outbreaks whereas Leon probably doesn't have to deal with BOWs all that often.
Need partner to carry me in RE6 mercenaries. PSN: Entropy19
Why are people assuming that Leon killed every enemy that he came across in 4? I highly doubt he killed even half considering he still was somewhat limited on ammo like all of the other games. In the movies they show him popping one or two every once in a while and ran, so I doubt we should assume storyline wise in 4 that he's mowing down everything that he sees.