Anyway here is the modified table for score needed in air realistic battles per rank after modifiers if someone wants:

I just so happened to have rank V french F-84G in need of spading (needed to get 7.7 CAS for Somua lineup) so Ive run first half of todays star with it. Its not BR I usually play (only other jet I somehow played properly in this BR range was the british Attacker FB 1) and I cant aim with guns if my life depends on it. Heres how it went:

Average time per battle: 00:12:54
Average raw score per battle: 1078,25
For the second half of task, I brought out the Su-33, which i also recently unlocked and wanted to continue spading it:

Average time per battle: 00:07:00
Average raw score per battle: 1559,43
Small sample size, I know, but I just wanted to demonstrate that score requirement is perfectly doable. Even with F84G, im sure i could cut the time in half if i played it as ground striker instead of fighter, but im not exactly fan of groundpounding in early cold war jets.
Further, if we take statsharks global average score per game for the last month, ie. circa 680 points per game, it would take approximately 30 to 40 games to grind out the whole task, depending on rank. Assuming person plays rank VIII and that the average time per battle remains the same, ie. 7 minutes, thats just 3 hours 30 minutes of gameplay for the whole task.
As themadseventeen already pointed out, you just threw yourself to BRs where you have no bussiness being, experience wise. You cant just jump from WW2 props to Hornets and expect to get instantly good.
Trick to events isnt to play as high BR as possible, but to play as high BR as possible where you can score consitently high scores.
So for you that would mean to play the german P-47D you have.