Please tell me more than 2 nameservers can help, when located on same location. For example I set three name servers and when test it from DNS records tool then show bigger time "s" for third nameserver. Is this bad or ok or removing third nameserver will help in any way?

ns1.xyz.com A 69.22.221.22 600s
ns2.xyz.com A 69.22.221.23 600s
ns3.xyz.com A 69.22.221.24 14400s

* Not a real IP’s