There is a reference in Ludovic Kennedy's book on Bismarck to various ''supernumaries'' joining Bismarck's company immediately prior to sailing on her mission. Included in these were ''a batch of midshipmen seconded from Tirpitz for war training.''
I am not aware of any other source repeating this claim and it is unclear what Mr. Kennedy's source is.
Were there any men from Tirpitz on board Bismarck?
I have sought the opinion of Jose Rico, who believes there were no Tirpitz men on board Bismarck and has confirmed to me that none of the men listed in the crew roster belonged to Tirpitz.