Should it be THE Shu, THE Wei and THE Wu? Or just Shu, Wei, Wu?

I see everyone referring to the upcoming Three Kingdoms factions as the Shu, the Wei, the Wu - even official age of empires communications - but does this even make sense grammatically?

Seeing as these are specific kingdoms, not people groups, isn't that nonsensical? Like saying 'the England', 'the China', or 'the France'? Should we be referring to them as just Shu, Wei and Wu instead? I was wondering if someone with more knowledge on the period could let shine a light on this.

This grammatical difference shows a difference between the Three Kingdoms and the 47 civilisations in the game. They're all referred to as people groups (eg: the Italians), but if you did that with the Three Kingdoms you'd just be saying 'the Chinese', 'the Chinese', and 'the Chinese'. I feel it'd be more congruent to just rename them to peoples like the Bai, the Xianbei and the Wuyue instead.