Any words of wisdom re: the arena fight list?

I started playing over the weekend, and this has been the most baffling part of the game. So far I've seen:
a list with players that can one shot kill me
a list of players my 1st guy can clear on his own
a list with only revenge options

My favorite though is when I have a list of 10 folks who have barely any tourney points, then the list refreshes with folks that have about 30% more points than I do (well.. I thought I had three more guys I could kill, kind of regretting that last double down...)

what gives? does anyone have any solid theories on how the list is populated?