Ok, I had a Deco S4 1200 with 2 access points. However I was still seeing a tone of drag when adding my devices, ie: ring cameras,  alexa & smart bulbs, tvs, Xbox, and PS-5's. 

Today bought a tp-Link Archer 5400. My hope was to add the deco's and the Google dots I had in a closet to extend the new 5400. 

However, found out quickly I can't use the Deco's.  However I have a ton of Google dots. 

My home is single story, but has been added to over the years. The total square foot of the house is 4000. And the age of the house is well over 100 years old. 

So here are my questions, and thank you so much for taking the time helping me. 

1. With as many devices and required bandwidth, should I create a network for each bandwidth or leave it to the router to determine?

2. Is it possible to just use the Google dots to extend the 5400?

3. Should I just use dual bandwidth extenders, however I would need to purchase?

4. Any advice would be greatly appreciated!!!