Like everything else we have to treat things with a grain of salt.
I know there are false pedigrees for OH's surname. There are 2 distinct families with his surname and one member (S) of line one became rich and famous and was childless. The other line was old money. OH is from line 2 but without the money
I have been told S claimed he was from line 2.
HH is a distant relation of line 2 but was considered a historian. He fabricated his line to be related to S so he could join the contesting of S's will many years after S had died. There is also a known herald (I forget his name) who was known to falsify pedigrees for money, so another reason to be careful.