Yeah but you dont see the top guys putting themselves in position to get ganged low and slow in any airframe.... period. From 5K to 15K the KI-84 is quite survivable. Under 5K your either running like Hell or dieing if your getting ganged.
The KI-84 may lack the dive ability to run like hell from a fight but it does retain the ability to regain energy and get back into one. The P-38 compresses too, and you sure as hell dont want to be low and slow on the deck with one, but from 5 to 15 K with its energy managed it can be lethal.
I honestly cant understand anyone who would make the claim the KI-84s guns are anything less then excellent. Its a premium, vs fighter plane, package. And a very good one vs Bombers as well.
But you see, the best position to fly the KI84 is 8K and below. It is probably one of the best planes to defend against CV planes. I always use it to defend against large CV raids, it is quick and agile agaisnt low F4Us and seafires. The La7 or the 109f would also be great agaisnt CV raids.
However, this type of fighting takes a lot of skills and SA to understand the situation. You have to get quick kills and be able to out manuevers other planes quickly to avoid picks. You have to be good defensively and understand defensive ACM. This is a challenging way to fly and it gets many people killed in their sorties, but you have to be aggressive. These fghts don't happen very regularly because defending bases is difficult.
Most of the really fast fighters like the190D, Temp, even the P51D, are a lot easier to be successful in because they are mostly flown at high alts and are generally carrying a lot of E when entering the fights. You don't have to defend as often because many planes cannot catch you. In most cases, fighting these planes Vs a KI84 is difficult because the Ki84 is in the defensive position while the faster planes can climb away and out of the attack. While the KI84 has a great accel speed, its overall speed is not that fast, even if the Ki84 out manuevers these planes, they can simple dive or speed away. It takes a very good understanding of defensive ACM like the BRD to be good with the KI84.
So while the KI84 is a great plane to learn and also a lot of fun to fly, it is actually a plane that is a pretty tough to be successful in in the MA if you aren't good at defending bases and setting up quick shots.