i can only speak for the new students those you call Empty Shells might influence...don't worry, we're not as gullible and easily misled by sempai as you would think
. it doesn't take long to figure out who can help us best learn---and it may even be the one you are concerned will show us the 'wrong' thing, though probably not. not sure when you have the chance to witness other students teaching, unless you are instructing that class...but i'd bet your sensei is as observant as you are, and can spot problems if they are there. i do think that if a sempai is too irritating to you for you to learn what they are showing, or if you are convinced they are wrong, or don't like their approach, you should discuss it with them (outside of class).