I often notice, when playing with new players, that their hero scouts and collectors on secondary territories or in treasure locations run around with troops that slow down their movement.
Remember, dear newbies!
There are movement penalty terrains – snow, swamp, and desert. You should move on these terrains with your native troops (i.e., units from the snow fortress, swamp, or desert). Don't think that if you have a harpy with a speed of 6, it will move faster on snow or swamp than a gremlin or gnoll, which have a speed of 4. There are no penalties on grass, lava, and underground. But here, as with all races, each terrain gives units a +1 speed bonus on their native land.
I think I described it correctly; if not, experienced players, please correct me.
So, if a hero, for example, is riding a gremlin and moves on grass, lava, or underground, there will be no penalty?