So I think I just discovered something that no one else has ever witnessed. I'm doing a playthrough of Heroes of Light and Shadow on Lunatic Reverse and when I got to chapter 15, the one from Shadow Dragon where you can only visit one of two villages to get either a Dracoshield or Energy Drop, something incredibly odd happened. I had save the villages from the initial Thieves and were farming the reinforcements coming from the center forts and right fort. The first turn of reinforcements were Thieves from the center and a Paladin from the right. The next turn Horsemen spawned from the center forts and a Paladin again from the right one (and this wave repeats for another turn). At one point two Horsemen and a Paladin were coming towards my army which I had set up at the island with the villages. I left a unit to take on the closest Horseman (and forgot the Paladin could attack him) and when the enemy phase began, instead of attacking me, the Horseman went to the village and destroyed it. A Horseman. Destroyed. A village. What the actual hell? Only Thieves are supposed to have that ability, so what the hell happened here?
I only have a theory that I have no way of testing, so if anyone can confirm or deny feel free to do so, but this is what I think happened. On Normal through Maniac, the reinforcements from the center forts are two rounds of Thieves, but on Lunatic above, the second round of Thieves are replaced by Horsemen, so what I think happened is that when the Thieves were replaced by Horsemen, the AI programming remained the same as if they were still Thieves and since he could have gone for the village, he did.