Some hosting providers use only one IP per nameserver and like GoDaddy many hosting panels don't have the multiple IP thing. There is not much difference between using the two combinations.
If you use NS1- two/three or more IP's then the request goes to all ip's and it will get your details through any one ip randomly(the one that works)
If you use NS1- IP1 NS2 - IP2 then the requests go to two nameservers and the data will be obtained from the nameservers.
In case you have both ipv4 and ipv6 then you can use IPv4 and IPv6 on one nameserver, so that both connections are accepted for both types on one nameserver itself.
It doesn't make an BIG difference between these two,so there is no need to worry much about it. Practically you don't have or need a number of IP's unless you are a hosting company
GoDaddy panel is huge and supports IPv4 and IPv6 IP's for consideration of failover issues and other stuff.
If you want to test anything, then you can do it by using these two combinations and see the difference in website dns. you can test your ip's for error using pingdom like tools.