The P-36 was pretty much an American Ki-43, but sturdier and better armament.
It probably would have done better against the A6M than the OTL in the P.I. based P-40E, that picked up a thousand pounds of weight over the earlier P-40B/C, and almost a ton more than the P-36, for a gain of 200hp was faster, but 1000 fpm slower in climb
The Mohawk was sturdier, but was still crippled by the common, far too light, armament of one .30 cal and one .50 cal. The worst feature of this is that it was entirely unnecessary to have that weak of an armament. The Finns would up have a pair of .50 cals, in the fuselage and four 7.5mm (i.e. .30 cal) in the wings with no noticable loss of performance (it is important to note that these were ex-French Curtiss 75) and Curtiss itself produced single versions of the P-36 with armament of 2x .50 and 4x .30 (P-36D which also had an upgraded engine raising the top speed to 311mph) and the "E" model (with EIGHT .30 cal
a la the Hurricane and early Spitfires).
The biggest advantage of the P-40 was, of course, much higher top speed, even after the addition of seal-sealing tanks and pilot armor, the "B" version of the aircraft was clocked at 352mph.
One of the really major WI of the Battle of France involves the Curtiss 75. The French rather quailed at the price of the Hawk, and kept putting off any sort of large scale purchase expecting the Bloch MB-150 series to fill their needs. The -150 series proved to be something of a dog's breakfast with well over half of the total production never being deemed combat ready (the first 157 airframes were never issues, behing held in storage pending upgrade to a truly combat capable configuration and many of the rest never having propellers and tail assemblies mounted). While it is doubtful that they could have saved the day, it is worth wondering how much different things might have gone if the French had be able to operation an extra 500-700 reasonably competitive fighters (the Hawk was slower than the B
f-109 but was apparently considerably more maneuverable and able to absorb more damage and stay in the air than the limited number of remaining Dora and early Emil variants). In combat the Hawk 75 had a likely 5:1 kill ratio vs the Luftwaffe (actual claims put the ratio at better than 10:1, 290 kills/80 probables against 29 Hawks lost, but claims are always inflated).