Isn’t that a bit like saying CNBC and MSNBC are “two entirely different and completely separate organizations”?
No, not at all. The GOP and NRSC compete - usually for money from the same groups of donors, but in other ways as well. There is no coordination - just like there isn't any coordination between the DNC and the DCCC, or the DLC. They are different organizations, staffed and managed by different people, frequently with different and competing objectives.
I know people would like to think that there is a "Republican Establishment". There isn't. It's folly. Washington is a back-stabbing, parochial even territorial place where everyone is looking out for number one. IF ONLY there were some real cooperation between these organizations.