I understand that most consider the P-51 the superior dog-fighting aircraft. I think that might be a little tainted as by the time the P-51 came in the Luftwaffe had lost many of its best pilots and their manufacturing and repair was impaired by them losing the war.
In terms of how much they are mentioned, it seems to me that the order is: Mustang, Spitfire, Messerschmidt 109, P-47, Hurricane, ME-262, FW-190, P-40, and then maybe the P-38 gets a mention at some point.
I also think that the P-38 did nearly all of the heavy lifting in Europe for the first half of the war - a critical time indeed.
When I see things on TV about the US Bomber campaigns, they act like we had no long range fight escort whatsoever before the P-51's were introduced.
I suspect that one reason for the lack of importance given was due to the P-38 dominating mostly the Pacific Theater; whereas most of the interest is in the European portion of the war.
As a side question: What do you think would have changed had the P-38 been fitted with Merlin engines and produced in large quantities? I know that this was experimented with; but there is little information on the results or the reasons this didn't happen.
The P-38's service in the ETO has not necessarily been overlooked, it tended to serve in an earlier period of the air war and in areas like the Mediterranean that tend to receive less press. It also was not an enormously popular plane for pilots, especially those flying the escort missions over Europe from the UK. Hub Zemke, who flew P-38s, -51s, and 47s, has a very good dissection of the P-38's vices and virtues:
-38--Though this aircraft had virtues, for me it was the poorest of the three US Army fighters in the European Theater. The fact that the extreme cold at altitude affected its performance hardly endears the machine. The turbosuperchargers were controlled by an oil regulator. At altitude the oil had a tendancy to congeal, which cause serious problems. On two occasions I recall, when entering combat with enemy single seaters it was a case of life and death to get away and survive, though I had started with the advantage.
On both occasions the engines either cut out completely or overran rpm limitations as the throttles were cut or advanced. It was enough just to regulate the engines and control the aircraft without entering combat.
The second serious limiting factor that detracted form the P-38's combat capability was its steep diving restriction--estimated at about 375 mph. A common tactic of the Luftwaffe single seaters was to split-S for the clouds or the deck. Oftentimes their head-on attacks on the bomber formations saw them roll over and dive for the deck to confuse and outdistance the flexible machine gunners. P-38s had little chance to pursue. When on defense, it can be easily understood that a dive to safety was the best maneuver for longevity.
Another factor to degrade the P-38's combat capability was the identification factor. The eyes of a pilot often picked up specks in the distance that could not be immediately identified as friend or foe. These were reported in as "bogies." Appropriate tactical maneuvers were taken to prevent bogies from having the advantage of a subsequent attack. In the case of the P-38 the twin booms and slab elevator gave this aircraft's identity away- as far as the eye could see.
It was also necessary for the P-38 pilot to do much more weaving to look down over the two engines that lay on each side of the cockpit. A better cockpit heating system could have been provided as my feet always froze at altitude.
Taken alone, the above statements would conclude that the P-38 had no outstanding features... it did! As a gun platform, it was steady as a shooting stand. With two engines there was no torque. With a little trim for buildup of speed (in a dive) a pilot could ride directly into a target.
As to the armament installation, I have seen no better. Four machine guns and one cannon in a tight pocket directly in front of the pilot. This armament being so closely aligned to the sight of plane of the gunsight required no convergence of fire as necessitated in fighters having their guns placed in the wings.
Though the P-38 had a wheel instead of the proverbial stick, this was no handicap- controls were light and response was excellent.
Relative load carrying capacity, the aircraft could take off with just about anything. I've taken off with a thousand-pound bomb under each wing and cruised with ease. On fuel consumption, the P-38 enabled us to cruise out to combat areas deep in Germany without the anguish of not having enough "petrol" to return home.
A tricycle landing gear made it much easier for a junior pilot to "spike the kite" on the runway and chalk up another landing. This was also an advantage in taxiing- a large engine and cowling did not deter from forward vision.
Note that a lot of the virtues Zemke lists of the P-38- range, load-carrying, heavy armament, good-low and medium altitude performance- were excellent virtues for a fighter operating in the Pacific theater. Even something as ergonomically mundane as a wheel instead of a stick helped aid the pilot in long Pacific sorties by lessening the pilot workload. Nor could the Japanese emulate some of the same tactics as the Luftwaffe. The lighter Japanese aircraft like the A6M did not dive terribly well. The October 1944 US technical report on the A6M5 noted that "the 'Zeke' is a most unpleasant aircraft in a dive due to heavy stick forces and excessive vibrations."
Overall, the P-38 has been given its due. The P-38 certainly receives more respectful treatment from historians than some other twin-engined fighters such as the Bf-110/410, Ki-45, J1N, or Fokker G.I. It was an excellent performer in some areas, but unfortunately for its vices were most evident in the one theater in Europe that receives most attention- high-altitude 8th AF escort.