Learn how to assign reseller accounts with their own private name servers such as ns1 and ns2 for their own clients in WHM.
Resellers can also have their own private name servers for their own clients making the server provider more anonymous and the reseller more credible.

Setting up Reseller Private Nameservers

Thank you

Is there a way to assign virtual namesevers (multiple nameservers on a single IP) through WHM other than DNS records?

I think there is an option in tweak settings to allow nameserver IP sharing.