Unlike wizards, who like nothing better than a complicated hierarchy, witches don't go in much for the structured approach to career progression. It's up to each individual witch to take on a girl to hand the area over to when she dies. Witches are not by nature gregarious, at least with other witches, and they certainly don't have leaders. Granny Weatherwax was the most highly-regarded of the leaders they didn't have. - Terry Pratchett