And then you have to chase it all over the map...
The computer sometimes exhibits rare stupidity with these small heroes.
Yesterday, I was playing against the computer, and on a high difficulty level. One of these small armies was running away from my main hero at full speed. A portal appeared ahead. I let out a cry, thinking I was about to lose the small unit. But no... The hero, after entering the portal, returned, then entered again, and returned again, and entered again. And it did this for its entire turn.
Why?