If you play an early jet correctly vs a prop, you are virtually untouchable in a jet vs prop match and can simply barrel stuff props repeatedly after banking and using energy unless you get slow and stupid, otherwise they cannot contest you.
However, given you apparently cant seem to go even near 1:1 in any plane you touch in gamemodes where people are actually aware of your presence even while spamming out rank 1 and 2’s, and have never touched another nation besides germany so you have no clue how any other nation’s planes actually feel to fly, it’s not a surprise you’re unaware of the consequences of downtiering planes, and especially jets into prop matchmakers, with no forethought as to how they effect everything around them, as long as you get yours.
Learn to aim the 108’s, and maybe go play a 262 vs props correctly, then come back, because I can very easily see you haven’t.
The p51h is absolutely busted and should go to 6.7 with the game as it is currently, and half the US prop tree is laughably handheld to varying degrees, which is why the knockon effects of just “keep shoving stuff down” caused by the terrible addition of all-aspect attackers would be disastrous for every nation at prop tiers if it’s allowed to seep down that far, as it would cause said cracked props from the US and other nations to move down and start clubbing lower tier props they shouldn’t see in turn.

