system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Where the fuck were these Lonely Mountain dwarves in LOTR when every one of their allies was battling Sauron?
gpt
Remember in the movies when frodo gets caught in that mini landslide and two evil men check out the area? Notice that those guys are heavily armored: they are not the same people that ride the elephants during the siege of minas tirith.

Heavy Armor = Men of Rhun (north of mordor)
Elephant Dudes = Men of Harad (south of mordor)

In the books, an army of 200,000 soldiers from Rhun descends on the reconstructed Dale (which was repopulated between the Hobbit and LOTR). The people of Dale take refuge in Erebor (the dwarf kingdom in the mountain) and besiege the mountain. When Sauron is defeated in the south, the men of Rhun lose morale and the forces of dale and erebor take the opportunity to strike the besieging army and rout them.

Legolas alludes to these events happening very briefly on their way to finding the undead army in the mountains.