I have a brother of William as a direct ancestor: Thomas Howitt, II
Also on the site MyHeritage there is a detailed Tantum/Howitt tree done by a user there. Both families come from the Derbyshire town of Heanor.
Joining would be great but I haven't found the connection between Pitsligo and Heanor. Would it be one of your William's kin that moved south or one of the Derbyshire Howitts that moved north?
This tree might help: http://www.myheritage.com/site-family-tree-151315251/derevo?familyT...