Why do we need it?
I can think of two major reasons why we would need an aircraft, it can do something no other aircraft can or it did something historical. P-40N did not do anything.
If the only reasons are that it's better than the E model and we have 5 P-47s then I give it a -1.
This could be about the dumbest response yet. Think of Spitfire models and their differences The P40N is a different P40, just as the Merlin P40s would be. Anyone paying any attention to the history would note the differences, who used them, where they were used etc.
I don't mind the argument that other birds should be added first, but that it didn't do anything historical is just silly. I suggest checking out the 5th Air Force use, the RAAF, the USAAF in China Burma India etc.
You'd be better off arguing that the E is pointless and the N is more important as there were 5215 P40N delivered vs 2320 P40E. The N saw a lot more combat and were around a lot longer.
If you really want to do it right, the AH P40 lineup would include the B/C Tomahawks, the Kittyhawks E and N, and the Merlin engined Warhawks F and L.
The skinners would be busy for years doing all the different skins available for that line up.
Consider it the same as having the Spit I, V, VIII, IX, XIV and XVI.