The wiki says that the only prerequisite for researching wagons is the wheel technology, however it appears that the secondary housing research (farm houses, lodges, hunting lodges, etc) have to be researched as well for the technology to become available. Since demonic races do not have these housing options available, the wagon technology never shows up.
Here's a save file of balrogs at the beginning of the gravity well challenge. The wheel has been researched, but no option to research wagons has appeared.
evolve-2024-02-09-21-26.txt
The wiki says that the only prerequisite for researching wagons is the wheel technology, however it appears that the secondary housing research (farm houses, lodges, hunting lodges, etc) have to be researched as well for the technology to become available. Since demonic races do not have these housing options available, the wagon technology never shows up.
Here's a save file of balrogs at the beginning of the gravity well challenge. The wheel has been researched, but no option to research wagons has appeared. evolve-2024-02-09-21-26.txt