I do not China and Russia has a lot of overlap in their military export. Russia has very limited capacity for naval export, UAV. MBT export to Thailand and Pakistan or even Bangladesh are not in direct competition with Russia. Exports in Aircraft are mostly to Pakistan and was ever a Russian arms buyer.
I am not sure that’s the case... I think the only item that doesn’t have overlap is UAV, where China can out produce with reasonable prices and is arguably more advanced in.
For naval side, much of the capacity will be taken up by PLAN for the foreseeable future and the primary market is the odd frigates, corvettes or costal patrol boats, much of the costal nation will want to move towards some form of shipbuilding for themselves should they be able to do so, additionally the nations that cannot/not financially viable to build but can afford it are mostly western nations which would not consider Chinese warships, thus the market therefore is relatively small, both in terms of potential customers and their potential budgets... perhaps naval weaponry and systems might remain big market, since even if the costal nations can build warships they might not have the array of offerings in terms weapons, missiles and systems. Not every country is India...
For ground forces, there would have big overlaps... the Russian’s offerings is quite well received from small arms to armour and China while having a big presence in small arms, have a relatively smaller one in armour but is gaining ground with new offerings in tanks and SPGs. I am sure this will be a fierce battle ground in the future, as China’s offering continue to improve in quality with competitive pricing. Also let’s not forget the other upcoming nations, like Turkey and Indonesia to a lesser extent, starting to have some new and competitive offerings, since ground force arms has by far the lowest barrier to entry. Again not every country is India.
I think the airforce is where it is at... this will be the single biggest battle ground... China was and to some extent still is hampered by the engine department... for the foreseeable future China will be building engines for its own use as the airforce continue to grow and improve... but once this nut is cracked and production go into full swing, the battle for market between China and Russia will be huge... the number of nation that can build their own jets or jet engines are limited and will continue to be limited for some time... most nations looking to build their airforce will have very limited offerings... and if they are not friends with the west or a ‘neutral‘ nation with a stupidly large budget then their options are basically China (I will put the JF 17 into the China camp here) or Russia and this market is slowly but surely increasing. In addition with China being able to build flankers, capable of using some legacy Russian weaponry, Russia’s advantage with nations already using Russian jets and is looking to update will surely shrink as time goes by, thereby becoming the biggest arms export battle ground between the two nations. I don’t think I need to repeat what has been said a third time.