No, he didn't forget the P-28H
WMaker's list has some I agree with, some I don't... I would add:
P-40N (ground pounder)
B-25J (mix of C and H features)
Bf109E-7 (with centerline bomb option)
He mentions Ki-61-I. There's a number of different ways of naming those, I want to guess he's suggesting the 4x12.7mm option. I would be for that but also would love to see (just as an option) the Ki-61-Ia, which had 2x MG151/20 in the wings. These were imported German guns and depending on sources outfitted between 200 adn 400 airframes.
It would be an interesting reversal from the 20mm-in-nose option we have now, even if the actual performance were no different.