Dark Elves vs. Mages.

I understand – the main question is, up to what level? You can even get around 15 knowledge points by level 16 if you try. I recently tried it against a mage, but the AI is too simple (veteran difficulty), and it only works sometimes (when the hero is chosen thoughtfully). It's better to rush into attack as soon as you've captured a few rare resources and have a good amount of gold. This strategy is designed for this type of hero, but sometimes it doesn't work out.