use your brain if you have, your military almost based of either Russian or European designs, please tell me What is J-7/J-8//J-11, even your J-20 is the Stealth version of Soviet/Russian MIG-1.44 design and similarly your Navy's Destroyers (Type-51 and Early version of Type-52 using Russian radars) and you went Ukraine to get AESA tech for your Destroyers
And who you're to put a verdict Russia is behind you in aviation fields, are you technical or military expert????
If you're way way ahead in aviation fields as compare to Russia why you're Using Russian systems like Su-35/Su-30/S-400/HQ12 (copy from S-300)
use the logic and common sense if you have
Weak link for Russia is $$$ but they are researching well with in the limited budget