This is because the Eurofighter flight model is based on a clearly defined set of requirements and performance metrics. In-game it meets and exceeds those requirements.
The Gripen FM is also based on publicly available information that has been interpolated. For instance there is AIAA article with turn rate graph and no values except JA-37 for reference. There is actually reason to believe that developers interpolation of this graph was based on old JA-37 flight model which also indexed the Gripen turn rate to be 1-2 degrees per second too high.
Rafale flight model is based on snippets of airshow HUD footage and by trying to cherry-pick the best numbers possible that would benefit performance. The HUD footage that is used shows a STR of around 20 degrees per second at 400kts.
The same set of HUD footage shows a bleed rate of around 21 kts per second for 8.8G turn from 590kts down to 480kts. There is also no indication that cutting throttle and using airbrake is part of the 2018 Rafale demonstration; the afterburner is visible in pretty much any external view of the 2018 flight demonstrations for the flat turns.
Currently in game, even with max dry thrust and airbrake deployed and on 30 percent fuel (higher than fuel load at this point in the actual demo), the plane does not bleed speed at the same rate.
The most recent weight reduction is based on a crash report of 2 planes where weight is specified and based on French bug reporter making argument that the lower weight plane is the more accurate one even though both planes are identical. They hand waived the weight discrepancies between the two planes by claiming the pilot in the heavier plane was potentially the size of “The Mountain” from Game Of Thrones, the lighter plane was piloted by the Elf On A Shelf, and that France can’t make a drop tank with a consistent amount of unusable fuel. Oh and that live ammo is used for an airshow because it’s labeled as a “tactical demonstration.”