BnZ you're missing the point Fugi is trying to communicate. You're fighting human pilots who make mistakes, not computers who fly perfect and make the best decision every time. If two computers fought each other 51 vs. K4 it would probably be a stalemate as the 51 would extend as it should when the fight gets too slow where the K4 will win. However, because we're fighting other people we can often fight the pilot just as much as the plane . I've gone toe to toe many times with Flyman's, Latrobe's, Grizz's <insert uber 109 stick here> many times and have held my own in the 51. You have to get a bit creative, but there is no need to go into the fight thinking you've already lost because a 109 is better on paper. Come in to the merge with a couple notches of flaps already down for a quick angles advantage and quick kill if they get careless. If they go vertical, depending on the merge you might get a good tracking shot, or just maybe pop off a quick burst to let them know you're there before breaking off and resetting. Remerge again with the flaps down and try for a shot again. If the fight gets slow, simply use your top speed to reset. Next time come in full bore with WEP and go for an energy merge, where you have a large chance of catching them off guard and getting above them, at which point you hold all the cards. At any point in this type of engagement, if the 109 gets careless even once you have a good chance of killing him. You just have to be patient and not get sucked slow for too long.
I went to the DA to train with one of the best fighter pilots in this game last week (someone you might not expect it to be). He offered to help me learn. Guy has killed me in the MA 1000 times already so I was glad for the offer.
We fought Pony against Pony several times. Then he went into different planes and situations. Zeke, Spit, 38, 109, Hawg. Co-E, advantaged, disadvantaged. He taught me some defensive tactics I need to work on.
His assessment: "You are a really good at turn fighting a Pony, you manage E very very well, and have exceptional SA."
(He also noted that DA skills don't translate to the MA in a direct manner. Which is true, as noted above by others.)
My hardest fights against him were in his 38. The Zeke and Spit were hard to hit but I had what some call "contempt of engagement"--I didn't have to fight if I didn't want to. The most success I had was Pony vs Pony. Hawg was a near stalemate--I lost.
My gunnery is atrocious at times as I don't lead enough and there are many times I am a fraction of available G short of pulling guns onto the target.
The key to success in the Mustang is the setup. TJ and Fess are exceptional at this. You can turn fight it all day long and still lose. I do it often, sadly.