I was watching a DVD of Sherlock this morning and it occurred to me that there's a certain similarity between Sherlock Holmes and Doctor Watson and Granny Weatherwax and Nanny Ogg.
Granny is incredibly talented - the best witch ever (possibly), but she has little idea how to deal with people, or understanding of their feelings. Nanny is like Watson to Granny's Holmes, in that she is her sort of moral compass. She watches over Granny to make sure she doesn't do anything too stupid.
They are both unlikely pairs, but best of friend nonetheless.
What do you think?