Neither Lisa nor Anders get annoyed at students mixing or skipping around from one instructor's course to another. In fact, I know for sure that both Lisa and Anders have encouraged this practice in the past, so long as the student finds it enlightening rather than confusing. I can't speak for Chris Schlegel though. He's wound a lot tighter than the other two and may well be a critic of such practices.

Personally, simultaneously drawing from multiple teaching resources is by far the best way for me to learn anything, be that music, calculus, medicine, tying knots, computer programming, etc. When it comes to teaching, every instructor has his or her own strengths and weaknesses so mixing the teachings of numerous instructors simultaneously makes good sense.

Sascha