The M80s will play louder than the M5s. But you may find positioning them in the room is a challenge and you may not be able to get them to acoustically disappear.

With that amp and subs, I can't see a benefit with M60s. M60s may be a detriment actually for the same reasons as M80s.

The M5s would sound terrific with as many subs as you want. I've used them with up to 7 subs. Fantastic!

The M5s are far less prone to position error than the larger Axioms. They are as refined as the M100 and active LFR and far easier to succeed with quickly.

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