I've got mixed feelings on this. It's pretty normal to have a daily theonite quest where you have to beat up a team with 4 times your fight score. And prize fights go up to 500% HP and damage, and some people manage that okay. But in the specific context where your opponent is also buffed with Sacrosact and Jinx it becomes really hard.
It might be a little much to expect people to do this at the bronze/silver end of the spectrum, which might justify adding some factor that scales it. It seems like it might be tricky to do though, what with competitors not always having the same rank.
Also I could swear the damage buff is actually much higher than listed, because I do high streak prize fights and occasional get hit, and it's not usually a "whoops, one or more your characters are now dead" situation.