I have found that ones too. I can understand why they do that, but I find it more challangeing to fight against AI alone if the difficulty is high enough, almost all the matchups I lost have been against AI alone. Funny enough that I have fought him, pretty boring match, we killed him all the time, probably he chose a bad character for that mission.
I hate when that happens, because I want my difficulty score to go up, so I won't surrender and go down on my difficulty score only because he want to play against some antagonist.
Sometimes is faster to do the mission fast than having to hold survives of 3 mins.
Edit: he is not the only one that does that, but if anything is done this will be extended because he is on the top of the antagonists.