Russia helped Syrian government to defeat clowns fighters in the past as Persian government request because Persian could not use their own air force because Israel would attack their air bases in Syria.
Assad asked Persian and Russian to leave Syria and they left.
Assad dis not ask any help from either Russia and Persia for last few weeks and he knew his time is over because of his lazy, crooked, corrupt military.
He made the right decision to go Russia for political asylums not Persia because of Israel attack.
HTS, al-Nusra-Front, and other clowns have people in Russia to get rid of Assad but it would be very hard.