Personally I'm struggling to understand how a P-12 would stand a chance against either a Gladiator or a CR-42. The P-12's max speed was 70mph lower than the Gladiator, and the disparity to the CR-42 was even greater. The P-12 service ceiling also topped out about 10K feet below either the Gladiator or the CR-42. The Gladiator had twice the firepower, too.
Don't get me wrong, the P-12 was a fine aircraft but it came a decade earlier than the other 2 types. There's no way it was competitive in the late 30s.
As long as we are thrashing an old thread, may I offer the Avia B.534 SrsIV which has been a favorite for many years. The captured units were used by Germany as trainers with a few modified to confirm arrested deck landing (on land) for possible use on the Graf Zeppelin.