I'd get rid of the side couch and move the back couch 3' away from the back wall and center it across the room. That would sound terrific with M5HPs, VP160, EP500, and QS10HPs on the sides. If you're planning Atmos, use M3s or even better, M5HPs on the sides.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated