Brooke, those stats are - by USAAF standards - pretty shocking,
compare them to how well the P-38 did in the PTO..
They aren't shocking if you consider a simple thought experiment. What if in the days before the P-51, instead of P-38's, the USAAF used 109's and 190's that could do long-range escort (i.e., other than magically giving them range, the same aircraft that the LW flew), gave them similarly experienced pilots to the Luftwaffe, and put them up in similar numbers to the Luftwaffe. In air to air combat, there would then be little difference between the USAAF and the LW, and they would thus lose similar numbers of aircraft in fighting each other. Now, if you substitute the P-38 for the USAAF fighters instead of 109's and 190's, and give them less-experienced pilots, and in lower relative numbers than the LW, and they *still* are about even, then you can judge that that P-38 is a decent fighter.
& on a cost analysis alone, it shows a significant win for the LW..
Indeed, the P-38 was a relatively expensive airplane. That's another good aspect for the P-51, which was relatively inexpensive. However, what hampered the LW later in the war was not cost of airplanes or production of airplanes but rather lack of pilots. The same was true for Japan. So history shows that plane cost is secondary.
They could not do that against the top fighters,
& [from memory] the Spit XIV was running 'bout 7-1 ahead..
Again, plane A < plane B does not mean that plane A is bad.