You do understand the difference between handwriting identification and the superstition of graphology, I hope. All this link shows is that two pieces of handwriting can be identified as being written by the same person. It has nothing to do with any of the previous posts and nothing to do with discerning personality from handwriting.
Do you actually consider graphology as serious science?
Just checking you knew the difference....

No, I believe there are far too many other indicators regarding JB's personality that give us clues.
And it's not so much how he writes but what he says when he writes, or doesn't say in many cases. I do believe he uses NLP when he communicates.