That's a very far stretch, challenge...
Very far.
The P-51 showed so much promise that the Army couldn't pass up on it. Only problem is the politics at the time meant they were allowed only close support/attack craft (politics, budget, or both). So they asked for a Mustang in ground configuration.
Not only was it unecessary, it was not "decidedly accurate and a marvel of engineering" -- no more so than, say, an SBD dropping a bomb, or a stuka, or a P-51D with bombs, or a P-40E with bombs, or a P-47 with bombs. Compared to the fighter-specific role of the RAF mustangs, there's a very good chance the "ground attack" version (A-36) had additional armor plating for its role, as well as the additional weight of the mechanisms to deploy the speed brakes. That's not counting the structural strengthening to add durability in dive pullouts, the ability to carry outboard wing bombs (which the RAF mustangs did not have as far as I recall seeing).
Might as well suggest the 190F8 was no different from the 190A8. Specific roles have specific requirements and have their own "baggage" inherrent with the design/production requirements. Fw-187 Falke was a very powerful plane for its time, great plane that could have turned the tide early in the war, but once loaded down with extra weight, a rear gunner, and "designed" for the zerstorer role, it was lackluster. You can't just say the Mustang and the A-36 were the same. Doesn't work that way. Close? Maybe, sure. Same? No.