Hi to all!
How some specimens of Bf 109 E will be equipped with (sub)variants of engines, armament, canopies... etc. not only depend what proposed by designer than also what available in the moment of production. It is also the same story when wrecked aircraft repaired. That repeated with later variants of Bf 109 even more than previous. So the features pointed out in documents understand only as guidelines but not as absolute truth.
Kind regards
Newcomer