Most overall weak faction?

[Musashi]

Yeah, I meant to mention that. If you have cav armies you don't have to fight siege battles even on the normal timescale, because you only need a few units to take every castle. Micromanaged well you can easily take on much greater numbers with cav. Divide and conquer.

[Olmsted]

This is something that is especially true with horse archers. Because they are so underpowered on autocalc, the computer often sallies on the first turn. Then you can totally destroy them on the battlefield, even with much lower numbers, and take the city very quickly.