Hi,
The Dewoitine D520 was probably the best design of the 1940s even with the Hispano 12Y. Many German aces, veterans of the spanish war like Molders for example, paid the price. In 1944 without improvement since 1940 the Hungarians with the D520 shot down B24 and P38.
The Gnome-Rhône 14N was the MB 152, MB 155 engine, the Leo 45 engine, the MB 174 engine, the BR 693 engine, the Amiot 354 engine, all planes without engine problems. The 14K was bad but not 14N. The engine of the Mitsubishi Zero was an almost exact copy of it.
The inferiority of French planes compared to British or American is a legend. Only the MS 406 could rightly be regarded as inferior to the Bf-109e but, in June 1940, it no longer constituted the main part of the fighters of the Air Force. From Dunkirk, no more English aircraft flew over France. The French campaign (from May 10 to June 25, 1940), except for the first 15 days, was a matter between French, Germans and then Italians. The film "Dunkirk" is in itself an insult to France. The Hurricanes or spitfires were not the only ones above Dunkirk, the perimeter defenders were the French, these are more than 84 French warships without counting the merchant ships which took part in the battle and the evacuation of the French troops. Just read the memories of the German military and Churchill himself to be convinced. It is true that France never considered Dunkirk as a victory but rather as a defeat ...not to say something annoying for the British!
JMC