yeah ..NO. Not even the US with there Anti Russian agenda go as far as making such a ridiculous statement. Russia is fighting the rebels AND ISIS, mainly ISIS but they definitely are going after the rebels too many of which aren't much better than ISIS. Taking out high level officials is good for press releases and PR, it does very little in the actual war as even the US have stated ISIS work with many people trained to replace anyone so that no person is essential. Palmyra is ISIS, this is where current Russian strikes are centered it seems.
That's a good PR but even if it was true, wiping out commanders and financial officials deals more blows than picking off replaceable minions.
you are dealing with a group of people that have zero respect for life and many of whom will happily strap a bomb to themselves and walk into the enemy if they think it is going to even slightly benefit their cause. These aren't people you can stop by taking out their leaders, it isn't a traditional army, such attacks on their officials I applaud, but if you think they are little more than an inconvenience then I think they don't understand the type of group ISIS is. The US's tactic of these targetted strikes had been going on for years all the while ISIS made further inroads, it wasn't until the Russians stepped in that the direction of this disaster changed.
For the Record I think Assad is as much to blame as the US for the current situation their and Russia's intentions are mostly selfish, but they are currently the only ones doing what actually needs to be done. What I think will be interesting is what happens after this war. If the US gets its way it will be a disaster, like it or not you actually need someone that is a bit of a pr!#k if you want to keep most of the extremist groups in check in the area, a soft puppet government will see the area erupt into chaos again.