Going by a quote from the article, thanks tallg, Hitler may technically be considered to have strong leadership skills:

"In Aristotelian terms, the good leader must have ethos, pathos and logos. The ethos is his moral character, the source of his ability to persuade. The pathos is his ability to touch feelings, to move people emotionally. The logos is his ability to give solid reasons for an action, to move people intellectually."

However, to refer to him as GREAT - blah. Surely there must be a sense of humanitarian sensitivity. And he had nought.

"Quit hanging on to the handrails . . . Let go. Surrender. Go for the ride of your life. Do it every day." Melody Beattie