The ability to scan and simultaneously track multiple aircrafts does exist in MiG29 and Su27. The place where these aircrafts differ are the ability to effectively target multiple aircrafts at same time and the number of aircrafts to track at a time.
You can also see that non of Su27 or higher variants of Su27 have thrust vectoring, while it exist in real aircraft. Only that you can do is Cobra maneuver. Su33 gets into spin very easily and is a nightmare to fly at slow speeds, while in real the canards are added to make the place more stable at low speed. So, Su33 is supposed to be more maneuverable at both low and high speeds but its not there so in LOMAC versions
I believe this would have been done for sales. LockOn might be selling more with western countries and no one would play LockOn if they are getting beaten by enemy a lot more. Think about it, F15 will not be able to survive Dog Fights if thrust vectoring of Russian aircrafts is allowed.