Board Thread:Suggestions Forum/@comment-25994755-20150308171850/@comment-26116279-20150308172315

the dwarves were not different shades of durins folk, they were all distinct cultures and clans each with their own leader they were independent of the longbeards but if the heir of durin called them to war they would come.

Of the elves there were the high elves and every other elf, the high elves of lindon were the noldor, in lothlorien there was a mixture of high elves and sindar, in mirkwood there were no high elves.

Rohan was a completely different country from gondor, dol amroth was a fiefdom of gondor, and all the other kingdoms of men were each unique not just different shades of gondor as you put it.