The Mustang: Heres my take. What is the Mustang? Laminar flow wing and high octane fuel, a Merlin engine and a massive fuel storage and drop tanks.
Laminar flow wings: Laminar flow: Smooth flowing air, not turbulent not stalled. No turbulent eddies. My opinion is that the Mustang’s wing was basically an anti-stall wing with the upside that it also didnt produce much drag, or lift. This is important for a high speed plane. Look at really high speed planes, they do not possess high-lift airfoils, because they do not need to. AND if they do need more lift, ie at landing, they simply deploy lift augmentation devices like flaps or leading edge slats. The Mustang’s airfoil had its greatest thickness moved aft and I believe this resulted in delayed separation of the airflow from the top surface of the airfoil. Thats the benefit. The thing you lose to get this benefit is lift. So in summary a laminar flow wing delays onset of the stall (Good for dogfighting), but is not optimised for lift production. But who needs optimal lift when youre doing 730KMH and you have 150 octane fuel?
I think the Merlin was built under licence by Alison (Or was it Packard?) in the US and at some point modified (Probably strengthened or something with the compression ratio) to use high octane fuel. To put it simply, an engine running on 100 octane wont produce as much Horsepower as if its running on 150 octane fuel.
The extra fuel storage is pretty straight forward, although Id say it would impact the weight and balance situation and would change the center of gravity throughout flight as the various tanks emptied.
What about that iconic air intake thing under the fuselage? What is that anyway. lol. I think it is a radiator.
What kind of fighter was it? Id say it was a high altitude fast flying turn fighter. Way back in the day Microsoft Combat Flight Simulator did a Mustang and I rather imagine it would be quite like that. Really fast and really good at turning and tightening the turn without dropping a wing.