Maybe these models are over-optimized for the monohull way of sailing.

First of all, the word document you linked indirectly claims that a sloop can outpoint a uni-rig. I don't see that out on the race course, in fact I think it's the opposite. Now it may be that argued that the uni-rigs I race with are mostly newer designs then the sloops, but clearly the lack of a jib dosen't hurt them too much going upwind.

Where the jib is a big benefit is when you turn the corner at the A mark. I can definetly head lower without stalling the main when running the jib then when the jib is furled. That, to me, is direct evidence that the jib accelerates the airflow on the leward side of the main at high angles of attack.

It may be that monohull sailors don't care about this effect as they sail downwind in more of a drag mode then an attached mode.