Here the announced article explaining why is the Russian Airspace Force (VKS) doing what it does in Syria:

Here’s the Key to Understanding the Russian Air Force’s Actions in Syria

I know that the WIB is not considered 'particularly authoritative', so let me observe that this feature is acutally a much compressed variant of a research paper about the VKS' doctrine and tactics - and a comparison of these with what we've got to see during its expeditionary operations in Syria of the last nine months.

Many might now wonder about sources of reference. Except for about 30 years of research about 'Arab' air forces at war with Israel, including affairs like training and equipment provided to various of 'Soviet customers' in the Middle East and Africa, these were such like:

- Russian Military Doctrine (in Russian)

- Russian Military Doctrine, 2014 (PDF file in English)

- KBP IA FA-2012 (that's the Russian acronym for 'Combat Training Course for the Fighter Aviation of the VKS'; sorry, it's not available online)

- very useful was also Russian Air Power at Crossroads

Anyway, the essential message of the entire VKS' operation in Syria is: when Russia gets involved in this fashion, then methods are irrelevant. All that matters is the achievement of political aims.