Um... so, here's the thing. I just started the second map and rearranged the units in the slots. It turns out that the Nomad doesn't carry the Serpent across the desert (no matter how I change their positions, they still reach their destination), but the Serpent carries the Nomad across the swamp (meaning the Serpent should be on the right, for some reason), just like Iron says!!! Can anyone explain this? :smile45:
Here's the thing...
If you're moving units in your army that are on terrain that you haven't explored, the terrain penalty will always apply. No matter how you position them relative to the units that are on their native terrain, whether you put them to the left, right, or even between the legs of a horse.
The exception to this rule is neutral units, i.e., those that don't belong to any of the castles you know (Nomads, Thieves, Wizards, etc.). They need to be placed to the left of the units that are on their native terrain, provided that, in your army, besides the neutral unit(s), there are no other units for which the terrain is a "penalty" terrain.
It's even simpler with the Nomad. Its presence in any stack guarantees that you won't suffer a penalty when moving across sand.