I'm only getting arount 2.6MH/s per RX 570 4GB. Is this normal? I should mention that I'm using Simplemining, so could that be the reason?
I'm getting 3 MH/s on one of my RX570, others are on 2.85 and 2.75 MH/s. Try with 1230/1500 clocks.

Also using SMOS