Some are probably Russian, some probably Ukrainian (or in the international legion).

Many 'other nations', too.

I take it to mean some people were on one side, some on the other.

Not one person playing both sides (but that probably happens, too).

I think he means that employees/contributors exist on both the Russian and Ukrainian side.

Yet another example of language ambiguity.

Considering the recent events in the area previously known as Yugoslavia, and the fact that part of hosting is there, in addition to Russia - Ukraine conflict being over a year old, I'd think of other sources. ...that if we were to trust what's been publicized, of course.