I dont think it is at all possible to separate the efforts of the Spitfire and Hurricane. Both were needed to defeat the Luftwaffe. One may have achieved more shoot downs than the other, but that is not to say the other, less capable type was still not an important element for victory. It is entirely plausible to say that whilst the germans were busy pursuing the lesser performing aircraft, the better aircraft was busy chasing down and shooting down the germans. Without that less capable aircraft, the other, more capable aircraft would have, itself, become a target.
In the end, the british victory came down to numbers. the more fighters it could get in the air, the better chance they stood of suviving. Eliminating hurricane production anytime from 1938 onward would have afected that availability of airframes.
The Germans maintained their 109 and 190 production for similar reasons.