Hi, sorry for late reply (never got notification) and thanks for your replies.
What I'm doing is exactly that actually, I have two dns providers, one in namecheap and then my own server.
I have the following as registered DNS servers:
1 - namecheaps
2 - namecheaps
3 - namecheaps
4 - myserver
5 - myserver
But on each provider they have different NS records (namecheap has 5 for it's own server urls, mine has my two server urls). Should I sync these NS records up so they each include each other?