i agree with everything there, except for human units from nurn. As far as i know the humans in that region were all slaves forced to grow food around the see of nurn (the only place in mordor where crops could be grown). They were a combination of newly captured POW's as well as the decendants of people that the dark lord had captured over a long period of time, so i doubt they would make for decent soildiers. at the very most maybe as a single, low moral, low quality, skirmishing unit