Originally Posted by
Aradan
That's how the AI works in RTW. It prioritizes targets based on the situation of the map (as it perceives it) and goes after them. There *is* a reason, or a combination of reasons, why Rohan doesn't want to expand into Rhovanion. It might like/fear Rhun more than you, it might find the provinces you have more desired/attainable goals, you might be holding some of its victory condition provinces, etc. Whatever the reason, it's not something we can really influence.
Yes, that was a bad attempt at forcing Harad to attack RK from the west. However, the AI only targets provinces that border its own, so once Andrast is lost, the army there simply tries to get back home. In the stupidest way possible on occasion. Harad doesn't start with the province in DoM, so that particular issue is not a problem any more.