Russians in Syria are fighting alongside Iranians and Hezbollah, they also have Chchens as a part of their forces. Fighting ISIS is at best 10% of their effort over there. They are mainly fighting against “Syrian opposition”, which is a set of many different groups, some (”moderate islamists”) are islamo-nazis, others are much less islamo-nazis than dudes fighting on the Russian side.
Obama’s ME policy has been crap but Putin's one is surely no better, they just have a different set of “moderate islamists”.
A prominent pro-Hezbollah newspaper in Lebanon reported Tuesday that Russia and the terrorist organization have formed an alliance and will fight together in Syria. "The parties to the alliance are the states of Russia, Iran, Syria, and Iraq, with Lebanon's Hezbollah as the fifth party,"
Al-Akhbar Editor in Chief Ibrahim al-Amin wrote. The pact would be called the "4+1 alliance", a pun based on the P5+1 that negotiated the nuclear deal with Iran. Hezbollah is a proxy of Iran based in Lebanon and Moscow has been working with Tehran to save Bashar al-Assad's regime, even sending men and weapons to Syria.
http://www.thedailybeast.com/cheats/2015/09/22/report-russia-partners-with-hezbollah.html