Studios almost always tend to hire independent producers to actually make films, and they provide (some of the) financing and have some level of creative control and influence.

Very, very few films are made directly by the big studios anymore. Moreover, Amy Pascal in particular is responsible for the output of four movie studio brands making a total of about 22 films each year, so she's never that deeply involved in workshopping unless it's necessary - the film is a huge tentpole or the film is in trouble.