Lack/limited subject knowledge by librarians

Although my research project does not have a topic/title yet, but I know I want to explore the notion of limited or lack of subject knowledge by libraraians, especially librarians working in branch libraries. In my case, the Built Environment Library has two schools, i.e School of Architecture and Planning; and School of Construction Economics and Management. As a librarian in this branch library, you have to deal with all the diverse subjects in these schools.To be able to offer research support, one has to have a little knowledge of each subject in each school. This is a huge challenge, especially if you have no background in any of the schools.
One,of course, can never enrol for all the degrees been offered in these schools, in order to be able to know the subjects. In my research I want to find out what are the other possibilities of knowing almost all the possible important things to know about the schools and the subjects, without necessarily enroling for the degrees they offer in order to be able to offer grea and excellent research support services?