Okay, let's assume you're right. After all, it would be very weird for any government not to have any involvement in a civil war occurring along it's border.

Why were there already separatists to be influenced? Why should accepting help from people you identify more with against people trying to kill you for that identity somehow discredit your struggle in the eyes of western spectators? How is this qualitatively different from Iran firing missiles into the zionist entity (Ukraine's self-declared role model btw) on behalf of Palestine?