There is nothing, and I mean absolutely nothing, in those two stereo amps that the surround amps don't have. If you look at the power supply photos, they are virtually identical across the products you referenced. The specs are virtually identical. A few tens of Watts won't make an appreciable difference.
Out of all those choices, I would definitely go with the Yammie. The built-in YPAO calibration, sound formats and other audio features will serve you well. Note though that it doesn't have Tidal (just get a Firestick). When you want to get into multi-channel, this receiver will do the job. It even has Atmos built in.
It is 6 Ohm capable so no worries there with the M5. When you get it, do NOT set the speaker switch to 6 Ohms. Leave it at 8. Otherwise it will fold back the voltage to the M5s and will reduce dynamics.
I think you'd be really happy with it compared to the other three.
