DNS Master - Slaves

QUESTION: If you get more than 1 server going, it becomes plainly evident that the DNS records should be shared across all servers. We have two name servers set up with our first server: ns1.domain.com and ns2.domain.com.

Now we will add a new server. How do we make it so that the new server still uses ns1.domain.com and ns2.domain.com? Is this possible? Or de we have to now use ns3.domain.com and ns4.domain.com and so? If we had 100 servers this could get maddening.

I see in the WHM where it says \"Estaliblish Trust with primary domain server\". What is that for? Does it address this issue? Any help/guidance is greatly appreciated.