The person who arrives with experience elsewhere still needs room to learn this place.

Experience transfers unevenly. Someone can be genuinely expert and still not know how decisions get made here, who to ask, what history sits behind an odd rule, or why the obvious improvement was already tried twice. Being treated as fully equipped from day one is a lonely position, because asking then looks like weakness.

Give an experienced newcomer the local briefing anyway, and say plainly that nobody expects them to know it. If you are the newcomer, ask the basic questions early while it is still easy.