I've found that the pathfinding is mainly good, but has a tendancies to place too high a preference on finishing on outposts (I think it does the same to resources, but outposts are high priority).

If you notice in the screen shot, it's set itself up to move through the outpost.  this is fine after you research roads to outposts, but until then, I always be careful and only move in straight lines.  either perfect diagonals, or perfect vertical, or pefect horizontal.  that way i can keep them on the road.

Doh, beat me to it! I second this. Really aggravating to have your own army try to pathfind around your own other army, especially when the army sizes are each one hero.

I think there's some bad english in the previoust statement...