There's a 3 level range in damage effectiveness so 28/29 -31 would have nearly equal opportunity against each other. The next factor is guns, doesn't matter what level you are, if your gun is maxed youre gonna do some damage! I played with my hunter at 25 earlier, I went up against 30/31 and could win because of maxed guns but I was -blam!-ed if they got a couple of good shots in because my armour is weak.