The match up is mojo not level although they are quite correspondent. In how the arena pairs. But you aren't winning 504 wins in week without resetting that arena. You can reset the arena 6 times a day with your daily quests granting a gift of 25 korbans. During an event you gain more added korbans. Giving another 2-3 arena resets. Now if you are somebody playing since the start what else do you invest your korbans on if you've collected everything else.

I'd rather the same equal system rather than a past exploit, you'd gang noobs, let's battle the level 10s, instead of it matching mojo or level or whatever it does, but you aren't gaining that OP math of 504 wins without resets.