Board Thread:General Mod Discussion/@comment-29145474-20170217010507/@comment-25101089-20170219025224

Yes, Rhúdel is supposed to be a Kingdom (as the Westerlings would call it) or a Khanate (the analogous term from the real-world analogue cultures). To be an Empire, or Khaganate, it would have to be much larger and/or comprised of many different ethnic groups. Look at some real-world examples of Khaganates and you will see what I mean. This was one of three main reasons we decided not to call it the Khaganate of Rhûn, even though we liked the name.

Rhúdel is similar in size to other Kingdoms in Middle-earth (Rohan, Gondor, Dale) but even when it was not called an Empire.

The Easterlings of Rhúdel make some references to their 'empire', but that can be interpreted as their own pride. Not everything said by a character in the mod is supposed to be taken as mod-canonical fact.