My understanding is that the medieval Spencer lineage has been proven false -- a deliberate fabrication by a corrupt herald in the 16th or 17th century, creating a fantasy connection to the Despencers. The evidence for this is mentioned right here at wikitree, in the profile of Henry G. Spencer at http://www.wikitree.com/wiki/Spencer-210 I'd like to suggest that Henry's "ancestors" be detached unless somebody knows of an answer to the disproof of this lineage.
And with that said, Henry G. Spencer, tied to the families of Winston Churchill, Princess Diana, and George W. Bush, deserves the best profile that wikitree can give him, so I'll do my part to get that profile into better shape. There is actually an image of the false pedigree on his false father's page; that could be added to Henry's page with an explanation. It's actually an interesting story, how newly successful people were motivated to "buy" a pedigree. The same thing happened with the Herbert family; my family tree is full of discarded make-believe ancestors :-(
A couple months ago I "discovered" that my ancestor John Spencer of Spencercombe was the son of Henry G. Spencer, and I momentarily got excited about the Despencer connection, until I read Henry's profile and realized that it just wasn't true. And then I quickly discovered that my John Spencer wasn't Henry's son after all, so I forgot about the mess on Henry's page until now.
Here's a link with a lot of quotes that could be used on Henry's profile:
Fact and Fiction in Family History
And The Complete Peerage condemned the false Spencer pedigree as "an elaborate imposture" which was "incapable of deceiving the most credulous": https://archive.org/stream/completepeerageo04coka#page/258/mode/2up
The November 1902 edition of "The Ancestor" had some fun with the Spencer family's fake pedigree, describing them as "that pushful house of shepherd kings" -- referring to the well-known true origin of the family's wealth. See https://archive.org/stream/ancestorquarterl02londuoft#page/188/mode/2up
Sounding a more gentle tone, Don Steel in the March 1996 edition of Soul Search, noted sadly that the pedigree forgery "obscures the real achievement of the Spencers of Althorpe. Alone, perhaps among the English nobility, the Spencers owed their riches and their rise not to the favour of a king or to the spoils of monasteries, nor even to a fortune made in trade, but to successful farming." See http://www.sole.org.uk/factand.htm