Despite all that (or for the reason that of all that), there are means of making use of this trope without falling into that pitfall. Twilight Sparkle is Cute Bookworm extraordinaire and the Only Sane Mare in Ponyville most of the time, but various episodes showed that she can be far more unstable and dangerous than the relaxation of the major cast merged, with just one scene from "Lesson Zero" taking the trope to an art variety.