Yeah i agree on the received damage.
we need something that counters that or just dont add the received damage to all classes. I can be certain that every other class would go for the received damage ( defender) just because of the flat 5 % reduction.
i like the idea, but I would think there should be no movespeed for the defender stat, instead it should be decreased. in this game where you can get received damage pretty high, there should be also dis advantage to it. just a idea, decrease by 20 %.