The Russian deployment of troops (about 4,000 so far) to Syria is not likely to ever include a lot of military personnel and Russian leaders are aware that they do not have a lot of popular support at home for Russians fighting and dying in Syria. In fact getting troops to go to Syria at all has involved using only true volunteers and paying large cash bonuses. This means pay of up to $4,000 a month for those at risk of combat, like special operations personnel and any troops who will be close to the front lines.
Russia learned the hard way in Ukraine that even among their most ardent nationalists there were few men willing to fight. The eager fighters were few in number and many are still needed in Ukraine (to keep the Ukrainian “rebels” in Donbas going) and the Caucasus (to keep pressure on Islamic terrorists down there). Russia is also increasing pro-war propaganda. But it has already found in Ukraine and Caucasus that this sort of encouragement has little impact the closer you get to the combat zone and none at all when you start shipping bodies back to families. So Russia is keeping troop levels (and friendly casualties) low in Syria and cash inducements as high as they need to be.