Very true. Also, some of the combinations of Catholicism and Paganism stem from Catholicism spreading onto countries with a very rich Pagan tradition. And indeed, South America, where I lived for many years, is very much like what you describe, and the clergy is more flexible.

Another thing, I believe, that makes Catholicism more susceptible to a mixture with Paganism is the fact that it's a much more festive and ritualistic relgion than Protestant traditions.

I strongly recommend the fabulous film "El Crimen del Padre Amaro" to anyone curious about the Church in Latin America. Granted, things everywhere are not as grim as they are in the film, but nevertheless it opens a window to these dilemmas and issues, and particularly to the life of Catholic clergy:

http://www.imdb.com/title/tt0313196/