The way I see it.. IDK if it holds any truth, but sometimes one can speculate.
The basic irony here, is that Russia has deliberately sabotaged Ukraine to keep government weak since dissolution of USSR. If they can prop up a corrupt, stupid, rapist pro russian president I would think they already have deep fingers in the intelligence services, the army, and probably even sleeper cells (now activated) to keep Ukraine under control.
So Ukraine suffers from bad government because of Russia, then people want to join Russia because the Russian propaganda makes them think its better there! Lol.
I can imagine the headache Ukrainian army and chain of command have nowadays.. They are probably facing immense intelligence leaks, deliberate sabotage by Russian aligned elements, as well as soldiers not believing in the cause.
@Butan.. about the firewpower.. I would guess 1 of those AKs have more firepower than all the pics of rifles you presented.