Currently I am planning to buy Deco (X50-5G) using 5g SIM for network access and replace fiber for network access. Currently I have a M4R router, and E4R router where they able to mesh togather. If I purchase the X50-5G and use it as main deco, can the router use for the mesh with M4 and E4 router? 

Just an additional question I got another router from Maxis ( TP-Link AR2140) which use EasyMesh can they connect with deco mesh?