My home is a  3 level house with ethernet wired on all floors. It currently has older Netgear Routers configured to be AP's on each floor with my Archer AX11000 position on the top floor at the rear of the house which faces the yard. In my garage I have a TP Link plug-in wifi extender (AC1900) to help strength the signal to my tv in the garage. My house is a double brick layer so the floors greatly reduce the strength of the wifi signals.

I would like to update the wireless system and have a mesh system added. 

I purchased a Deco AC1200 m4 3 pack and configured them as AP's to do some initial testing with some poor results. (Not integrated wifi, slow speeds)

The AX11000 is the most stable router I have ever used and I would like to continue using it. On the AX11000 menu, there are options to add a mesh system.  Is there a DECO system that I can upgrade my wifi coverage. Look at the website the Deco AX3000 with the Backhaul feature should be a good fit but will it integrate well with my AX11000?

I don't think I have any 6e devices to take advantage of the pro version. 

Thank you