Bending a knee means nothing , once Jon bends his knee to Bran .They already bent the knee for Jon, plus no one is going to follow a cripple.
The North always remembers .
Plus Bran is the most powerful of all the stark kids .
He is cripple to those who do not him , and he is more than a cripple to those who know him .
Once he masters his sight . He will be able to see through time .