Roger, sorry for 'changing' your name, call it temporary mental disablement.
Otherwise I do not agree with the numerical superiority argument. It is a common excuse but I would hardly call it a decisive factor. At least not in the context.
Kutscha, in 1950s they flew at 14+ kms, perhaps at an earlier date they were not cleared for more. Nonetheless note that mentioned 13 km (have not checked it) is an operational altitude which is still 1,5 km more than the maximum ceiling of Me 262. Add to this obvious problems with intercepting the target and it means Spitfire 19 (post war marking) was untouchable.