And how much "advice" to they give? When I went, the only time you had to talk to your advisor, was once a semester for them to rubber stamp your approval for major-only classes (which the official advisors would defer to in-major professors). Beyond that, you were free to talk to advisors on an as needed basis. There role was essentially to be a primary point of contact for students. Why shouldn't a student have multiple advisors. If she has a problem/question with her honors program, ask the honors advisor. If she has a general administrative question, go to the general advisor.

Our entire math department was served by two advisors who likely also had non advising administrative duties.

My honors advisors were just the main faculty of my honors program.

I don't think I ever spoke to my official CS advisor.