China at the time must have had a shortage of experienced test pilots, both aircraft never survived their maiden flights.
That would hamper any aircraft's development .
The XP-0 looks a lot like a P-36, but according to the Complete Book of Fighters, it had a steel tube fuselage, and wood framed wings, so completely different from the P-36, under the skin.
Any performance figures have to be just estimates, but I do wonder how they expected about 360 mph out of the XP-1 with a 710 hp engine.