I had another thought: there are many empty garrisons on the borders of the lands on the map. Maybe we could populate them with some units to make the atmosphere more immersive? Otherwise, you cross a country's border without a single battle, which doesn't make sense...
In addition to this, I suggest the following: give the "Thunderbolt" ability to the "Giants" and have the hero's army consist of them – then the visualization would be more logical.