not saying weather the formula is right or wrong seems pretty acurate to me though..........
a 220 fixer would have near 7k defensive rating without perks up at 220 with those calcs. Personally that seem kinda insane. with perks up I would guess 10kish didin't calc with perks up so thats just a guess. with that kind of defensive rating FA shouldn't land but onces in a blue moon and from what I hear it lands more often then that.
personally I believe there is some form of hard cap on evades and AR keeping everyone in check but, there is no real way of telling if there is or isn't unless someone from FC steps in here