[Belegorn]

Yea it was probably not Morgoth. Basically in that lore his forces were trying to turn Men away from Eru, so they rebelled against Eru and some later rebelled against Melkor. However, it was was claiming "I did this..." or "I did that..." such as creating the satellites and stars, but Varda is the one to do these things and the Valar made the Sun and moon. I'm not sure who among his servants are speaking as Melkor himself, but at least in this lore from Andreth it appears that Men were really only set on the road to rebellion, and not used much or amalgamated into Melkor's forces. Some of the Men were given power, but otherwise I don't get the idea that there was some grand plan here to put Men to use other than to delude them about who was who.