Flynn might have many good qualities, but the Deep State walked all over him last go round. He might have learned something from the experience, but the next round requires someone with a very strong grasp of the law (enough to stay out of trouble and ahead of legal games the swamp will play), plus a dose of ruthlessness.
I completely agree with the necessity for the quality of ruthlessness in all of Trump’s selections - VP, Cabinet, judges. We are in a (currently) Cold Civil War, declared by the Left, and we will need warriors in all positions of leadership.