I am planning to buy the Deco M5 but first I'd like to confirm whether the backhaul via cable would work connecting the 3 devices at the LAN ports of my TP Link Archer C9. So basically I was thinking of the following:

Modem > Archer C9, then connect the three Deco M5 using ethernet cables at the Archer C9 lan ports. From my understanding the Deco M5 should be configured as AP. It would work? 

I really appreciate your help in this matter.