Sorry to say but Russia will not join Pakistan and China in any anti-western alliance . The Russians and Westerners too have made a move towards each other now .They are no enemies .
Plus this news about Mig-35 is not official , its just a suggestion to the Russian govt. by some Russian expert which may well go unnoticed .
Russia will not lose a partner like India for Pakistan by having a defence relationship with them , for sure .
Economic and trade relations ? sure why not .
No matter how much some chinese and Pakistanis may want to see a Pakistani-Chinese-Russian alliance against the west . i don't see it happening .
Pakistan and Russia are also on the opposite sides in the Afghanistan issue and the West and Russia are on the same side .
Sorry not happening .