I am going to replace our old Archer c3150 with a BE9300. I probably want to add at least one extender, possibly two extenders to get some better coverage at the corner of the house. And also to support about 100 devices (TVs, phones, tablets, chromecast devices, alexas, home automation devices, etc). I have one location in mind where I have an Ethernet connection and another one where I don't. So I am looking for the best solution for a standalone device that plugs into an Ethernet port (ideally PoE) and one that is just a repeater that plugs into an outlet (I don't really have anything there to put it on a shelf, etc). 

Btw, I was also considering an AXE4900 which already comes with the main unit and 2 extenders and supposedly accomodates up to 200 devices. But it's 6E rather than 7 (not sure I really need 7, though).