Board Thread:Suggestions forum/@comment-26168781-20160227192413/@comment-26298013-20160301211017

Mr Hobit is correct. Every creature, sentient or not, fought on both sides of the War of the Last Alliance. The only species that was completely undivided were the Elves, who, as he said, followed Gil-Galad. There were VERY FEW Dwarves on the side of Sauron, but there were some.

Numenorean armor is a very reasonable thing to have appear in these areas. Given that the Numenoreans had fled their homes just about a century before the battle, they would still be using weapons and armor from and designed after those from Numenor. For all intents and purposes, Gondor and Arnor were two provinces or states of the country of exiled Numenoreans.