Well, as much as I like Serbia and the former Yugoslav as a country and culture, I am actually not a fan of many of these small countries. Maybe it's because I am a bit too sensitive and nationalistic as a Chinese. They could have been a lot more open to Chinese military equipment exports like some ME country and SEA country and most of all, Pakistan. Yet, at times, they would rather receive Russia's flashy junk Mig-29s than the latest J-10C.
Of course, I won't blame Serbia, because Russia at least donated some of the Mig29 to Serbia for free. But if Serbia really treat China as a great friend, they should retire (or donate) all their Mig-29's and Soko J-22's and ask China to give them a good deal for 24 J10CE. Or, they could keep their Migs, and opt for replacing their junky Soko J-22 for 12 to 24 JF17 Block 3. Both these options would take care of their defense requirement for sure.
I think you're setting some strange standards if your like or dislike of nations is dependent on their willingness to buy Chinese military equipment.
Viewing it objectively, for many Eastern European nations, it is only until recently that Chinese military exports were of a sufficient quality to be seen as desirable alternatives to Russian equipment, and that region is indeed the Russian MIC's traditional stomping ground.
Whether they buy Chinese arms is also not simply a matter of need, but of money. If they lack the money for it, then they simply may not be able to afford certain weapon types and categories, if China will not provide attractive prices (versus what might be available for say, a closer ally like Pakistan).
Additionally, China's ability to effectively market key weapons systems in those markets, compared to competitors, is also a major factor. That is something China can only praise or blame itself for.
Expecting those nations to be as receptive to Chinese arms as a nation like Pakistan, ignores all of the geopolitical and materially qualitative and financial factors involved.
Heck, there may even be some weapons categories that China may
not be willing to sell to some Eastern European nations.
So I definitely do not think this idea of "if XYZ nation is a
good friend then they should buy weapons". That's just not how the international arms trade works, and it isn't even how the geopolitical factor of how international arms trade works.
