@Brazilianhip 

Hi, welcome to the community.

I think Archer AX6000 could replace the BT smart hub, then we still need to connect the first main Deco M5 via an Ethernet cable to AX6000.

And there is one more thing about the Wireless networks of AX6000 and Deco. They will still be separate Mesh networks.

Can Deco Mesh, OneMesh, EasyMesh and Omada Mesh products work together?

So we usually suggest turning off WiFi on AX6000 and setting Deco M5 into Access Point mode.

How to set up Deco to work in Access Point mode

 Thank you very much and best regards.

  @Brazilianhip 

Hi, Thank you very much for the message.

I believe you have the third(last) connection with the ONT modem here:

https://www.bt.com/help/broadband/getting-set-up/how-to-set-up/bt-smart-hub-2

When the Ethernet/WAN port on the BT smart hub 2 is connected to the modem, the BT hub works like a wireless router. AX6000 and Deco M5 also work as wireless routers by default so in most cases, they are all replaceable. If you have no issue with BT smart hub 2, using ISP-supplied equipment is always the first choice.

No matter you choose Archer AX6000, M5 or both, AX6000 or the first main M5 needs to connect to the 1-3 Gig Ethernet port from BT hub 2.

ONT modem goes to the WAN.

Wan port on AX6000/Deco M5 goes to Gig Ethernet 1-3.

It would be better to set AX6000/Deco M5 into Access Point.

If you want to replace BT hub with AX6000, please connect the ONT modem directly to the WAN port on AX6000.

After that, if you used to put a PPPOE username and password on the BT hub 2, now you might need to set up a PPPOE connection on the AX6000 and input the same internet credentials.

Thank you very much and best regards.