For the bravery, I thought about the rule of the old skirmish system of the 6th Edition of Battle :
During the Rout phase, if a model count less friend model than enemy model 3" arround him, make a bravery test : roll 1D6, if the result is smaller than the bravery of the model nothing happen, otherwise its next move must be a disengagement move.
A 6 is always a failure, unless the bravery is above 6, in this case, you can reroll a failed test.
(I hope it's understandable...)