Different difficulties

[Omanes Alexandrapolites]

Hmm, that's odd. I have never experienced any problems comparable to that before in M:TW. From my experiences, you only have to chase the AI if they have horse-archers, but after their missiles have run out they usually charge. Sadly, I've seen what you are claiming has occurred more in Rome and BI and have lost many battles because the enemy refused to fight tactically and instead decided to run around the field.