An item in DC Velocity opens thusly:

Gen. Duncan McNabb, commander of the U.S. Transportation Command (Transcom), tells the story of his meeting with Secretary of Defense William Gates when he was assigned to the post in September 2008. Gates, impressing on McNabb the significance of his new job in the midst of two wars, quoted Alexander the Great, saying, “My logisticians are a humorless lot … they know if my campaign fails, they are the first ones I will slay.”

• via Military logisticians honored for meritorious service – DC Velocity.

While I can imagine Alexander saying something like that, I can’t imagine him saying it exactly like that (especially the ‘humourless’ bit) … anyone know a source for Alexander saying something similar?