LordoftheBrownRing wrote:
Who were some of Arnors bigger allies? Was Gondor a help back then? If so Im guessing the heros in the movies who were men generally werent alive to help. Maybe a warband of Rohhirim Led by Eorl the young? Or is Mirkwood a good thematic choice?
They didn't really have any allies until it was too late.
The Elves and Gondor were busy defending their own lands against attacks from Mordor and elsewhere. A combined army of Gondor and the High Elves was sent to relieve the last Kingdom of Arnor (Arthedain) but they arrived a year too late.
Fornost was besieged and sacked, and Arthedain was destroyed. The King, Arvedui, fled north to Forochel but drowned when the Elven ship sent to rescue him was crushed in the ice floes and sank. The few survivors who remained, including King Arvedui's son and heir Aranarth (who later became the first Chieftain of the Dunedain) joined the Gondor/Rivindell army which marched to the ruined city of Fornost and destroyed the army of Angmar.
The Witch King was forced to flee, and his Kingdom of Angmar was destroyed, but he had achieved his objective of destroying Arnor.
If you want Elven allies, I'd use Elrond, Lindir Glorfindel, Erestor, Rivindell Knights and High Elves. Glorfindel was present at the Battle of Fornost, and it was the presence of such a powerful Noldorian Elf that forced the Witch King to flee.
The Dwarves had a number of cities across Eriador, in the Blue Mountains and Khazad Dum (which had not yet been destroyed), and there would have been trade routes throughout Eriador, so you could use a Blue Mountain or Khazad Dum themed allied force. Though no interactions between the Dwarves and Arnor are explicitly mentioned in the appendices.
When Arvedui fled north to Forochel, he sheltered for a while in an abandoned Dwarf mine in the northern Blue Mountains, so that would make for a cool scenario. Maybe Arvedui was being pursued by Orcs, and the Dwarves sent a force of Dwarf Rangers to rescue him.