1. Your K/D ratio in the P-51D last tour was not earned attempting to engage co-e Spits in turn fights. Whether it came mostly from application of E-fighting, picking, buff-hunting, or deliberately isolating and then running down and shooting A/C that the Pony can more or less match agility with, I do not know. Note, I have nothing against you, all of these methods constitute correct ways to use your airplane. I am only saying your relative success indicates what you were NOT doing with your Mustang.
2. 1v1 ACM problems, in order of easiest to most difficult, assuming more or less equal pilot skill.
Level One- Successfully prosecuting a turning engagement with an opponent in a similar or worse turning machine. Most people can learn how to do this consistently against typical MAers from a couple dozen hours in the TA/DA.
Level Two- Successfully prosecuting an E-fight against a decidedly more maneuverable opponent. Now, excepting the occasions where someone gets greedy and bites on a rope, this is an order of magnitude more difficult, in no small part because of greater gunnery challenges. You will not have the opportunity to get on an opponent's six and hammer away for a protracted period of time, as you will when you gain the upper hand in with a t'n'b machine.
Level Three- Overshoot fighting, in which the opponent's craft holds all the cards and you must basically entice him into making a mistake. Overshoots are not necessarily that difficult to come by in all circumstances, but the fact that you will likely get only 1 shot makes insane gunnery and prediction of exactly where your opponent will be crucial.
Of course, the typical MA fight is anything but 1v1, thus generalizations are hard to make. It would have to be admitted that faster planes toward the "BnZ" end of the spectrum are easier in the sense that it is possible to disengage from situations gone sour more often, but are not necessarily easier to get lots of kills in.
