Time Capsule Basic Question

Hello Folks,

I have gone through a few threads here and learned a lot but I still have a basic question.

What is the best configuration for a Spectrum Modem/Router that gives me the fastest wireless speed using two Time Capsules?

I'm confused about the differences between roaming and extended networks.

My configuration at the moment is a Spectrum Ubee DVW32CB Advanced Wireless Gateway. This box is the main modem/router (bundle includes Cable TV, phone and Internet). From there I have two Time Capsules, one is a AirPort Time Capsule 802.11n (3rd Generation) and the other a AirPort Time Capsule 802.11ac. Both TCs have the latest software, are connected via ethernet cable to the modem/router and I am running MacOS Sierra 10.12.6 on the MacBook Pro that I access all three appliances.

Using the Airport Utility, I have "factory reset" and disabled "Network" mode and turned off the router "Off (Bridge Mode)" on the two Time Capsules. My Ubee Modem/Router has the Wireless Bridging "disabled".

Both the 2.5 Mhz and 5 Mhz are setup and active.

Is this the correct setup?

Thanks, I appreciate any guidance.