It is Just a lame excuse mate If we continue to develop things like this there would only be a single innovator(i.e. USA) and rest will just be followers( Neuron etc.)
Even chinese have come with a different (and unique) design for their future UCAV and Trust me even the AURA will be based on...
Su-27 is a different thing. It was related to security of their country and under the sanctions it was the only possible way for them to make cheap copies of that plane in large numbers in house.But you will see that they even degenerated the names of original brands e.g. NOKLA , STAR *UCKS :lol: