Evil things

[Hot, crispy nice hobbit]

Actually, the Numenoreans had set up colonies in Middle-Earth even before the Sinking of Numenor. They set up their fortress in Umbar, which is somewhere south of Gondor and Mordor, where the Haradrim lived. The Numenoreans probably mixed with the people of Harad, which have been drawn towards Sauron, and hence became Black Numenoreans...

(Gotta stop... the premises for racial discrimination is too high)

But Numenoreans aside, I am really much more interested in another group of Men which fought on the side of Evil: The Dunlendings. By all accounts, these Men are just normal men, and do not seem too evil. There was serious Bad Blood, of course, between the Rohirrim and the Dunlendings, but that was because of Land Grap. (Seriously, if Gondor was not so troubled by the East, would you think Rohan could still exist?)

Saruman deceived the Dunlendings into fighting on his side, but there was no actual account of the Dunlendings fighting alongside of Sauron. In fact, the Dunlendings were so deceived by Saruman that they thought the Rohirrim would burn them alive after they lost.

No Orcs remained alive; their bodies were uncounted. But a great many of the hillmen had given themselves up; and they were afraid, and cried for mercy.
The Men of the Mark took their weapons from them, and set them to work.
'Help now to repair the evil in which you have joined,' said Erkenbrand; 'and afterwards you shall take an oath never again to pass the Fords of Isen in arms, nor to march with the enemies of Men; and then you shall go free back to your land. For you have been deluded by Saruman. Many of you have got death as the reward of your trust in him; but had you conquered, litte better would your wages have been.'
The men of Dunland were amazed; for Saruman had told them that the men of Rohan were cruel and burned their captives alive.

But let's face it, Prof T did his best to assume the historian, and ascribed wicked deeds to not just the 'Men of the East and South'. Various dastardly deeds were also done, and not just by Men, but Dwarves and Elves. So I should say that the 'gift of men' is obscure, in that it dishes out freedom to every mortal man, but serves no justice.