Can I use a TP-Link AC750 mesh wifi range extender with my Deco E4? If so, will there be two different network or one single network?

My deco E4(Single Pack)'s network is congested on a daily basis. I have to optimize the network daily once or more than once in some days. I have no more than 8 devices connected to my network. Most o

I am currently using a deco e4 router. Now I want to add a deco m4 as my primary router and add my previous deco e4 to this network. Now I want to whether deco m4 is compatible to connect with deco e4