I did a comparison of top speeds between these jets, on both sea level and around 5200-5300m of altitude where you avoid contrails because high altitude top speed is somewhat irrelevant anyway. The test is made with clean aircraft and min fuel.
At 5300m max afterburner(gripen on just 101% or else rip wings)
So, apart from the Gripen being able to supercruise and having low drag, but still, I was not expecting these results… Actually I was expecting to be the other way around, the F-15 to be the faster, then Flanker, and finally Gripen. In-game the Gripen on 101% afterburner is almost as fast as the f-15 going full blast at 110% while only producing like 33% of its thrust (on 101%)
Apart from speeds, I think the FM’s are decent, but I feel like the F-15 is overperforming in energy retention and underperforming in AoA.
I am by no means an expert on the issue and I would like to know everyone else opinion.
Here are some graphs for these three planes at the alts you describe. In the gripen’s case its low drag makes all the difference. The F-15A just loses thrust at high speed letting the su-27 which is even draggier pull away. Pretty sure this is historical, as the F-15C has the more powerful engines to go mach 2.5.