As explained by an F-35 pilot last year, dogfighting against the A-4 is still relevant today for several reasons:
The F-35’s sensors and “fusion” provides me as a pilot with good situational awareness. For an F-35 to simulate an opponent against another F-35, it has to restrict the effects of fusion and the various sensors. Even then it is difficult to “dumb down” the aircraft enough. It requires discipline to not be tempted to using information that an opponent in reality would not have access to.The A-4s we faced in these exercises had sensor performance along the lines of our own upgraded F-16s. They also carried jammers intended to disturb our radar.The pilots we faced were very experienced. We are talking 2000 hours plus in aircraft like the F-16, F-15E, F-15C and the F-22, with detailed knowledge of “fifth generation” tactics and weapons. When also cooperating closely with intercept controllers on the ground (GCI) they could adapt the training and offer us a reactive and challenging opponent. Note the word “reactive.”The A-4 is a small aircraft with a corresponding signature. Many potential opponents in the air are bigger and easier to find than the tiny A-4.
I'v always thought that if a number of other operators had been persuaded to do the up-grade(USMC included), there would be a continuation of operational use of these great little machines. There's probably further up-dates that could keep them flying. isc