Yes, those are very important factors.And IMO it has a clear industrial political aspect: CAC alone cannot produce all fighters for the PL and having as well as retaining a second team capable to develop and produce fighters is keeping technological and industrial sources.
I was just talking with @latenlazy about this actually. We saw the guy that got interviewing saying that J-35's core research team had average age of 32 to 33. That is so crazily impressive to have a young group of engineers that are involved in such a major project and will be around for decades to come.