Can I set FOUR domain name servers?

[Francesco Moi]

Hello.

I've got a domain (foo.com) registered at myregistrar.com, and 
two web hosters (webhoster1 and webhoster2).

My domain registrar lets me customize my domain's name servers. So, 
I set four servers:
ns1.webhoster1.com
ns2.webhoster1.com
ns1.myregistrar.com
ns2.myregistrar.com

My webhoster1 lets me to create a lot of subdomains, so at
ns1.webhoster1.com (and ns2), I set sub1.foo.com to be hosted
at webhoster1.

My webhoster2 has an IP (33.33.33.33), and if access to 
http://33.33.33.33, I access to my webpage.

So I set at ns1.myregistrar.com that any petitions to sub2.foo.com
be redirected to 33.33.33.33. And I don't mentioned anything about
sub1.foo.com.

Will this work? Will petitions follow nsX.webhoster1.com for sub1
and nsX.myregistrar.com for sub2 ???