Else you might as well call the degree "rote" because that's what you measure.
> maybe fails in intro courses
If someone cheats their way through intro courses they are up for a bad surprise since the upper level courses assumes a mastery of the intro classes!
I'd still point out that the system is not robust against: - Working in groups. (Bad if tests are supposed to assess individual performance.) - Asking outsiders for help.
Also, your downplaying of "rote" learning feels misguided, no matter how advanced/abstract/high-level the domain in question is. Cue the Bruce Lee quote about 10,000 kicks..
We are so used to exams being about doing stuff that literally nobody in real life would ever even consider.
However, I'd assume that doing either during a test would be against the honor code.
Students hate carrying dead weight so to speak. Sure they might be tempted to swap favors (A helps B for a certain subject and the reverse is true for an other one). If the exam is properly constructed you might be able to detect plagiarism however.
Rote is absolutely necessary for a well rounded education, but I really feel the need to overcorrect in the opposite direction because testing for rote is the lazy approach. Over time a lot of testing has the tendency to shift to simply measuring rote.