Fatigue:
From the official MAK report:
Captain flew 32Hs and 40 minutes during his last month, 15Hs 35 minutes during the last 3 days (7 sectors) and could rest for 15 hours before flying in his home.
Note: most night flights, some emergencies on-board. From 11-12 of September he had significant infringements of the duty times and time off.
First Officer flew 12hs and 35 minutes during his last month, 5Hs and 20 minutes during his last 3 days (2 sectors) and could rest for 15 hours before flying at hotel "Nord"
Training:
Captain received initial B737 training at FTI, Denver, in 2006. His last sim was in 16th of June at Lufthansa Training Center. He didn't get much line training time when upgraded to captain. FTI was not approved by the Russian authorities at that time and the Captain had to fly the TU134 for 4 months after being trained for the B737.
First Officer received initial B737 training at St Peterburg GU GA, Russia, in 2008 (training didn't meet all the Russian Authorities requirements). His last sim was on the 22nd of June at Lufthansa Training Center.
Pilots didn't get English language training at proper approved Centers, no upset recovery training.
Plus the maintenance issues like a impressive throttle stagger.
I might be wrong, but i think there's a shortage of pilots in Russia. Did they ever consider hire some expats? Even from other CIS countries? Well, maybe it would be too costly...