Hi, I'm technically illiterate and I've just had a new broadband connection installed and the ISP installation included a TP Link  with one Deco M4 router. The system is great in the locality of the router but I need/want to install a wireless mesh system to cover the whole house and garden. The installation guy said I should get a set  of 3 by M4 but I have done some research and would prefer X50 as it appears to give better performance and range . Should I connect them to the existing single M4 or would that be limiting or otherwise unworkeable? Or maybe I should  use the single M4 as an outlying unit?