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.
What they had and what they planned to have was two different things, Castle Bromwich taking longer than expected to get into production.
The Hurricane may very well have been steadier, and not only less prone to sideslip but less prone to other deviations to the desired path, a result of not being quite a sensitive on the controls. I am not a pilot so just putting that out there.
Many web sites/articles claim the dispersed guns on the Spitfire didn't hit to the same place due to the wing flexing, This on an airplane that had one of the fastest diving speeds of any fighter in WW II without the wings falling off. Seems more than a bit strange.
Anthony Williams book "Flying Guns World War II" has the expected patterns for a Spitfire with a 350yd cross over centered on an HE 111 from 6 oclock for both 75% and 100% patterns.
at 300yds the gun patterns for basically an over lapping sideways figure 8 with the 75% patterns being smaller in diameter than the fuselage. The patterns over lap by around 25%.
At 400yds the bullet paths have crossed over and you still get a sideways figure 8 only larger. 75% zones are now slightly larger than the diameter of the fuselage and the overlap is closer to 50% (depending on gun/s).
This is hardly the "all over the sky" described by some pilots. Of course with some pilots even in training opening fire at 900 yds or more bullets were certainly going all over the sky, but not due to any fault of the aircraft design (of either type).
Next page has a few deflection charts. If you are shooting at an He 111 that is doing 250mph and you are at 400 yds and 11 1/4 degrees off the tail you need to aim over the wing tip or just outboard of the wing tip in order to hit the fuselage over the wing roots. If a pilot is overcontrolling his plane it might seem like the bullets are going allover the sky?