I can't speak for the CZ-USA and CZC connection, but I have little doubt CZ-USA would stand with CZC in the event a valid warranty issue surfaces.
I know CZ-USA works very well with CGW, and we have never had an issue with a valid warranty. This is not saying CGW does warranty work for CZ-USA, we simply warranty our CGW work and products.
So CZC, CZ-USA, or CGW, you potentially have 3 x a warranty; the customer is the clear winner.