Hmmm. So how come in 2015 the SBU said that there were only 56 Russian fighters in Donbas?

https://www.kyivpost.com/article/content/war-against-ukraine/sbu-registers-involvement-of-56-russian-in-military-actions-against-ukraine-since-military-conflict-in-eastern-ukraien-unfolded-399718.html

SBU Chief Vasyl Hrytsak said.

"We documented involvement of 56 Russians in the military actions against Ukraine from the moment the military conflict unfolded," he said at a press conference in the village of Pyatykhatky, where the SBU basis located.