I know this is a mesh of several cultures, but the names throughout the History are extremely confusing. Under names it states Japanese (ending in vowels of 'n'), yet most names do not follow this. There is even a Nicklaus in there.
Of course these can change over time; they could be a combo of several cultures, etc, but it does sound odd. I actually like a lot of your made-up names, like the clan names, but I think some clearer direction would also be good.
I would even suggest Province variations. Some + Japanese-like; Mountainous province could use Nepalese; Coastal ones Korean, etc. Or a complete mix of any of these. You might even want to bring in the Russian influence, though names like Nikolaus have more roots in Greek etc and sound odd here.
I stated this under Giants, but I would take the Russian influence and combine that with the Giant culture. It would suit better. I mean the first 'Rus' were Vikings, so that suits the Giant origins too (as giants elsewhere have names derived from old Norse etc).
So far, I have had humans use Korean and Japanese (or made up names ;)).
Some thoughts/ideas/direction here would help :) (These can be new thoughts, from other people too).
βIt is amazing what you can accomplish if you do not care who gets the credit.β β Harry S. Truman