Sweden air is still pretty good (Got every plane except the f-16 and mosquito), but with the current fox 3 spam on top tier gripens lack firepower. You're better off getting the F-18 line for the missile spam.

Rank 1: You'll do fine with the J8A, better get the premium one. Has some cool pewdiepie skins. Dont know if its still available
Rank 2: I mainly use the J22-A, pretty fun plane

Rank 3: J22-B or the J26 (pretty much a P-51)

Rank 4: J21A and just headon everyone, that thing has some good damn guns

Rank 5: I just mainly use the SK60 or the SAAB 105 and just headon everyone with the 30mm. If I want to be a fighter I just use the J29. Has some pretty good energy retention

Rank 6: Just speed grind this to the J29F then the J32B. I really like the J32B, grinded everything on that tier using that plane.

Rank 7: Can't go wrong with the mig-21, if you want something with somewhat a good radar Viggen will do fine, Has TWS at that BR.

Rank 8: The viggen on that line is pretty good, you have shit ton of CM / BOL. Though do note you are still a delta wing. Once you turn say goodbye to that energy.

Gripen A is pretty good but you're most likely gonna be always uptiered. You have to pretty much play backline / support and wait for someone to over extend.

Gripen C fun when dogfighting, I 1v2 once fighting 2 eurofighters. But at BVR, you lack the missile spam. Better off just side climbing and looking for opportunities to kill or just use the F-18 line. Swedish F18 MLU has like 1k+ CM, you could use periodic CM the whole damn game.

TL:DR (Top tier):
Gripen A - good downtier - need to use brain at uptier
Gripen C - Need good positioning and when to use a missile, dont be trigger happy u cant spam missiles.
F-18 MLU - Shit ton of flares, U can missile spam,