Official statistics reports that 5+ percent of the Ukrainian population is staying/working in Russia. Only in 2015, about 1 mln Ukrainians arrived here seeking for work and better/safer life. And only a minor part of them is from Donbass (Crimea is totally excluded from this statistics). If there was a war between Russia and Ukraine, do you think they would do it? Can you imagine French of British people massively and volunteerly going to Germany in 1940?
There was mentioning of "top Russian lies about Ukraine" some posts above. No doubt, Russian mainstrean media often lies, I agree. But the same about the western media and similar "collections of lies" do exist addressing opposite direction. Truth is indeed difficult to find and in the civil war all sides are both to be blamed and both have "their own truth".
Mentioning Russian troops in Ukraine is so much beyond average russophobia that even official Kiev is not using it that often. If there were regular troops there, they would be in Kiev in 2 days and you would have crowds of current Ukrainian establishment members knocking your British doors crying for asylum. Donbass is a large area that inherited a hell amount of weapons and military industry. No doubt, there are foreign advisors on both sides. Like in Syria where many western advisors help folks like an-Nusra (read Al-Qaeda).
One more point: it always amazes me when people who never witnessed anything consider themselves as experts (I mean not forum members, but media and journalists). EU and US people write articles and books about Russia-Ukraine and likes trying to "teach the locals". Imagine that I would start talking about issues like "Britain vs Northern Ireland" or "England vs Scotland" insisting that UK people "do not know all the truth". It would be correct "to offer me some hard erotic treatment".
In general, I find this discussion quite fruitless.