Now sorry about this but there is no way on gods earth I can span a first fret F (6th string) to a 5th fret A (6th string) it is just not possible for me!

Same here. No amount of practice will change that for me. But I usually find it is not so important. As you pointed out, Django had two fingers and a stub. Wes usually played with only three of his left-hand fingers and, as far as picking is concerned, down-strokes with his thumb were quite sufficient.