And I'm not sure I agree with your understanding of who's dreaming at what levels. Certainly we know who the caretakers are, but I don't think that has any relation to who's dreaming - - though even Page's brilliant Architect character seems to have been confused on that score.
The first level - the rainy street level is Fischer's dream. That's the whole point. The team can enter his dream, but he is the dreamer. They design the maze and invade it.
Putting aside the fact, then, that all subsequent levels are still Fischer's dream - I believe it's explicit that he's also the dreamer of the snow level, but I'm not sure who's the dreamer of the hotel level.
I don't know why I like this movie; I HATE videogames.
But since Yousef is the caretaker of the dreamers IN Fischer's dream of the rain level, it's clear the caretaker and the dreamer are not necessarily related. Arthur does not have to be the dreamer of the hotel level simply because he then becomes the caretaker there.
Lukas Haas, the earlier architect, was not the dreamer of any levels he was caretaker in. It was somebody's dream within Seito's dream, but not Lukas's.
Oh Christ, now I'm even confusing myself.
