On the idea of a 'limping sheep/leader'. See e.g.:
'If a sheep wanders off too much, to protect it from getting lost or eaten or whatever, the shepherd will actually snap one of its legs! Then, since the thing can’t walk without great pain, he has to carry it around everywhere he goes. He puts it down in the green pasture, he sits it by some water, he picks it up when there is danger and puts it in a safe place. Then after a time of being held by the shepherd for so much, and being weakened and limping from the permanent injury, the sheep stays close to the shepherd the rest of it’s life.' ('A Flock of Limping Sheep',
http://www.biblescribbler.com/2009/08/a-flock-of-limping-she... )
'The Shepherd never leaves their side though. He uses his staff to direct and guide the sheep towards the pen and the sheep will gather close to the Shepherd for safety. If however, a sheep goes astray, the Shepherd will, lovingly, break the leg of that sheep. He will then set it and carry that sheep the rest of the way. (Mike says that a strong leader usually walks with a limp.)' ('Oh, To Be A Limping Sheep',
http://iwascreatedformore.blogspot.co.uk/2011/02/oh-to-be-li... )