500 was the number at the fall of France, an almost equal number of Spitfires and Hurricanes, it changed quickly as pilots returned and planes were produced. It is from that base that your numbers are produced, the Hurricane massively out produced the Spitfire to the point that Park used one as a runabout, the issues were pilots and pilot expertise and the number of Spitfires. As far as I read, not being a pilot the Hurricane was less prone to side slip and had its guns all together, many said the same of the Typhoon. I would never argue that the Hurricane was the equal of the Spitfire, I would argue that 750 or 1000 Hurricanes are superior to 500 Spitfires, especially since in the BoB the vast majority of kills were made by people unseen by the victim. In a fur ball or mass fight losses on both sides were comparatively low, the Spitfire being best for inexperienced pilots.Basically the RAF had 31-33 Squadrons with Hurricanes in the BoB (some were nowhere near London and Channel) and 19 Squadrons of Spitfires (again some were nowhere near London and the Channel). You had a few other odds and sods types of "fighters" scattered about.
Calling it 31 squadrons of Hurricanes and 19 of Spitfires means that Hurricanes made up 62% of the force (not counting the odds and sods) so one would expect them to cause 60-62% of the German losses due to fighters if the Hurricane was equal to the Spitfire. If it is 33 squadrons then they should have done a bit better.
Most accounts (many of the online accounts are dubious and don't even compare the correct models of aircraft) say the Hurricane shot down about 55% of the German losses due to fighters? Losses of Hurricanes are slightly higher at 63.7% but that is really too close to call.
Please note that most accounts claim the Hurricane was a better gun platform, although the reasoning leaves one scratching their head a bit. Not saying it wasn't, just questioning the reason/s given in some of the accounts.
The 500 aircraft (Hurricanes and Spitfires) sounds a bit low although it could have been true at some point in 1940 (May or June?) or a number of the squadrons were under strength?