I am no expert on Billy Graham, but I do know that he comes from the most extreme(Bob Jones) environment. While he backed away from that, he always appeared with short hair, suit and tie.
Not that short a hair-do. It was pretty long for those days. But nonetheless, I am afraid I was being contentious.
I have a pretty good knowledge of BG, although like you, I am not an expert. However, I was in my teens as BG influenced many of us through Youth for Christ in the Chicago area. He, and the other young guns of that movement were rock stars...they weren’t my Mama’s preachers by any means.
You are right that BG did go to Bob Jones University, for about a semester, but Bob Jones, Sr. split with him in 1957 (that split began a little earlier). You might be interested in knowing that Bob Jones IV attended Notre Dame as a grad student...but I don’t know for how long and whether he took a degree.
You can find a picture of Tullian at Christian Book Review dot com and see his “spiky” hair in a review of his book “Unfashionable”. You’ll see that he is not extreme in the least, and at least if he’s under 40, I would hope he doesn’t dress like me. BTW, you can see a lot of BG in him, though he is more swarthy.