You are confusing it Bro - or at least me in the bargain.
Karzai came with a laundry list of supplies that he desired from India and India obliged by lining up Russia to be the supplier, the Afghans are used to Russian arms anyways. This deal has nothing to do with Russia and China desiring to increase their global arms sales and competing with one another.
Yes, Russia supplies to Iran, China, India, Bangladesh, Burma and have begun supplies to Afghanistan too, but what does that have to do with their intended supplies to Pakistan and NK?