Heroes 6 - Discussion

I'm playing the Rise to Power map on the maximum difficulty setting. I've defeated everyone except for the Haven faction (the AI is strong). Their heroes move twice as far on my territory (with a -30% penalty from the Sands of Ash artifact) compared to my heroes. I have boots with +4 movement, logistics and pathfinding skills are maxed out, and I have +5 from the stables and statue (41 total). Is it possible that the opponent has more than 80 movement points? Yes, they have +30 to +40 morale, while I have 0 (undead). Am I missing something, or is this a bug? It's impossible to play; the hero can run across the entire map in 2-3 days...