Interesting the Disney Wholesale confirmed that sleeps 5 info - never would have occurred to me to ask them, was a great idea!
But, my next thought is how trustworthy their answer is, you can often get 4 different answers from 4 different CMs.
I just don't know enough about the distribution of room types at YC myself to answer your question about comparing to the PE listings. Think I might try looking through Touring Plans' room finder to see if I can get a better feel for the room types, as I'm curious now!