The Su-35BM is NOT at all a Su-35 upgrade. It is essentially a redesign aircraft. Modified control surface, rework structure, totally different flight control sys, avionics, powerplant all sums up a new aircraft form sketch. Less content under the both topic does not give reason to merge two different aircraft under one single title. This will confuse readers that does not aware the difference of the both aircraft and is an irresponsible way to present information.