I'm playing the Templars on H/VH, and have seen a disturbing development in the Mongols. In SS 2.2, the Mongols appeared, immediately went to war and usually had two or three towns within ten years.
In my current game (SS 3.0 with UAI 1.3 incorporated), the Mongol arrival was announced and soon after they were reported (in the diplomacy menu) as being at war with the Seljuks. Well, I had spies everywhere, but could not find them until about 20 turns later when they surfaced around Yerevan. There seemed to be several extra stacks, because the Horde was truly looking like a horde. Very scary. However, they didn't attack any of the Seljuk or Byzantine cities they were clustered around. They just strolled here and there doing NOTHING, until about 15 turns later when the bulk of their armies wandered into my territory and attacked me. I held a bridge against three of their armies and from that time on, they stayed in my territory (around Edessa) milling around and bumping into each other, but not doing anything. I took out a couple more of their armies and assassinated most of their leaders (with the new ridiculously overpowered assassins). In a final battle, I killed their faction leader and the Horde disappeared.
What could be causing this aimless , strolling behavior? Any thoughts?