No, by that logic all airplanes are derivative of what Wright Brothers flew in 1903.
As far as Su-27 and Su-30MKI is considered you name one parameter which is common, either all systems are new or upgraded, Compare Engine, Radar, Canard 2D Vectoring........ Capability from electronic or aerodynamic point of view..........If there is any variant close to this then its Su-37 not Su-27.
One is generally known by its previous generation not by 2, 3 or 10 generation before, just like most people know you or I by my/your father or mother name.......yes few know about your grandfather or you might find someone who still remember your grand grand grand father.
In fact if you read about history of US aerospace industry then you will find that F-22 is heavily influenced by design of F-15, no not complete stealth shaping but wing shape and mainly its radars (only few know that the main weapon of F 15 is not its speed, endurance, missiles or load carrying capacity but its radars), that's the only reason for its 105:0 kill ratio, off coarse weapon, training and few other things also played its part. But ever heard of F-22 being called as derivative of F-15?.... NO. Not just because they look different but there is more to it.
Ask someone who flew both Su-30MK and Su-30MKI about its radar, aerodynamic or other characteristics.......No its not me neither that person shared with me about technical stuffs....because many things are classified about Su-30MKI.
No more off-topic discussion on this thread.