DC DNS Settings

Hi, I have four domain DCs.

What would be the preferred IPv4 'DNS Servers' order on the NICs?

DC01 & DC02 are on one 10Gb network and DC03 & DC04 are on another 10GB network.

The two networks have a 1Gb link between them.

This is what I'm thinking but any advice appreciated.

DC01

DC02

DC03

DC04

Loopback

DC02

DC01

DC03

DC04

Loopback

DC03

DC04

DC01

DC02

Loopback

DC04

DC03

DC01

DC02

Loopback