What makes Dominic an historian but not Tom?
What are the bonefides that Tom is missing that cause sources to refer to Dominic as an historian but Tom as an author? For example this entry https://en.wikipedia.org/wiki/Goalhanger "In November 2020, the company launched The Rest Is History, hosted by historian Dominic Sandbrook and author Tom Holland." Even on their own wikipedia entries, Dominic is referred to as an historian while Tom's entry adds the modifier "popular historian." Is it Dom's thesis on Eugene McCarthy that throws him into the realm of full historian legitimacy?