The levels of your team look fine to me, I would not consider anyone there to be "noobs" and they are all far from falling into the criteria of mentor match status. If I were that antag, I'd definitely be playing to win.
Like Drow said, being level 500 or 999 is just a number. Once you hit level 200, there's nothing beyond. 199 is max forge and 200 is final set of character cards. I'm willing to bet I know the lv 500 player too, there's not a whole lot of them. At least 2 or 3 people in my regular group are that high. I would be, but I play other games and don't have as much free time, so I'm just mid-200's. Again, level 500 is statistically no stronger than someone my level.
@Hiero-- so again, it sounds like you are suggesting a player at an astronomically high level is just plain not allowed to play the game, because levels seem to be the most important measuring stick? I've lost to teams much lower than me and won against teams higher. Level is just a measurement of play time. There are stats involved, but not as large of a difference as many make the claim to be, and they cap out.
For a player at level 500, 600, or even eventually when the cap is hit, when someone is 999? What is the imaginary like that you would personally draw at play vs. no play when you have to sit in queue to get randomly matched? We've gone over this so many times already, if I'm going to sit in queue, and I happen to get matched up against some low-mid levels, that's not my fault. It really isn't a dick move to just want to play the game, no matter what kind of grudge you have against antag mode as a whole.
I don't play as much as I used to, but when I do, I'm not turning the game on for 4 hours to sit out 4 or 5 matches because there's a level 2 in every match. Which is what it sounds like you're suggesting, lest I be pulling "a dick move"