I think there are several factors at work. One difference is in the structure of the clubs. CUFC is run by, and its teams are coached by, part-time people. There is not nearly the pressure for wins and titles that I believe exists at CESA. Consequently, you just aren't going to see CUFC coaches scouting the state and region for players to come join their teams. It just doesn't happen. CESA does that, and they do it successfully. That contributes greatly to the perpetuation of its success. They win, which makes it more attractive, both to "recruits" and to those who might take their own initiative to move there, which creates better teams, which win, which makes it more attractive...
CUFC seems happy to have kids from everywhere try out. I have not meant to suggest that CUFC has a policy or preference that discriminates in favor of Midlands kids. On the other hand, I don't think you'll see CUFC teams replacing players after tryouts with kids they "find" elsewhere.
I should also make clear that I don't speak for anyone but myself and I don't know every single thing that goes on with every team. There may be exceptions to what I've described as the "culture" of the Club.
People are free to characterize what I say as rationalizations for CUFC's relative lack of success at state cup. I prefer to see it as more of an explanation (partial) than a rationalization.
Bottom line - CESA, as a club, cares a great deal about adding soccer balls to its website. I think that is less important to CUFC. Some may argue that it should be more important, and that is perfectly fair. I happen to like the way we do things. I also accept that it hamstrings our ability to compete across the board with CESA in terms of championships. I'll repeat that I don't think there is a morally "right" or "wrong" way to do these things. I just have a strong personal preference in the matter.