It was a single seat AT-6 / SNJ and was not superior to the P-36 OR the P-35.
I think it would have made a good fighter-trainer and have seen one fly many times in Arizona, where at least two were created by converting AT-6's. I even flew in formation with one once in the back seat of an AT-6. They could cruise with the better WWII fighters, but were hopelessly outclassed when the P-38, P-39, P-40, P-47, P-51 etc, added power to reach for the upper end of their performance envelopes.
The P-64 cockpit was single seat and the wings were shortened a bit from the AT-6. It was a "hotter" ship than the AT-6, but was no first-line fighter though, in the absence of first-line fighters, it probably would make a good aircraft for back areas or remote theater where little first-line opposition was expected. It was and is relaible and rugged, just had performance more in line with the early to mid 1930's than the 1940's.