I think one of the next teachers, 4th or 5th, should have a stealth-hiding component, like the Granny mobile game, where unlike Viktor who knows where you are at all times regardless of stealth, this new teacher would aimlessly search the floor seeking your location, and you cannot juke or outrun this teacher if they see you, like Marzia and Doggos. The teacher will rely on sound to find you, and dropping items, notebook beeps, and any other suspicious sounds can alert the teacher where you are. Oh, and unlike the other teachers, this one can turn their bodies at different angles like Freek-a-del'ka, Doggos, and the librarian, so if you see the teacher's backside, quietly back the f#ck away. I don't think door-opening will count as an alarming sound, because other characters can open doors too. There will be a few hiding spots around the classrooms and corridors, only a few, because a lot of them would be too easy. There will also be a lot of traps, like bear traps and tripwires linked to bells, probably like the war siren that some of us have heard, or the normal school bell, that other enemies in the game are smart enough to avoid, while the player is prone to making noise with said traps. The h-teacher's punishment will probably be a guillotine, like the one in the Granny game.
One more thing, I bet Baldi will be the geometry teacher after being promoted from being a simple math teacher, if mrdrnose doesn't get a copyright strike, that is. He looks like a geometry teacher alright.
Biology teacher:
Geometry teacher: