Morning everyone, sorry but I am clearly in a minority here and I will explain why I disagree.
IF the family tree had been written in the modern era "on the back of a chip paper" I would immediately dismiss it.
HOWEVER it is not. It is held according to the information above within the chartulary at Broomhall, the family seat. Assuming that is the case then we must assume the Earl of Elgin and Kincardine, both current Chief of the Bruce clan and more importantly the acknowledged most direct male descendant of the mediaeval Bruce family believes it to be accurate.
I often cross swords with Wikitree members who are used to publicly accessible, often digitally available sources. I have on occasion rummaged through old family papers in chartularies belonging to distant cousins while working with them on mutual family research. Most such papers are family papers, private and not open to public viewing. Indeed the earliest Sutherland family title deed, dating from 1165 appears either temporarily lost or mislaid (not by the current Sutherland family) but its contents are accepted pro veritate because distinguished early 19th century historians and genealogists stated in writing that they had examined the document and translated the contents from early mediaeval Latin into "modern" English.
This year alone we have altered the position of two well known men within the Sutherland of Forse family because distant cousins had stumbled across wills, not readily accessible and not digitally available, which showed that the men in question were both "brother german" to the men whom generations of historians had claimed were their fathers.
I would therefore argue that where a document is believed to be in the hands of the correct family and has in the past been seen or verified by someone unlikely to "make it up", that source should be accepted. In the course of "rebuilding" the main cadet lines of the Sutherland family over the past 30 years, I have used all sorts of scraps of information, few if any publicly available and while any one may be open to challenge, taking them together, as we lawyers might say, they begin to corroborate one another and build a clear picture.
I certainly would not object to a research note appearing on any profile indicating that there may be some question as to the validity of the claimed link between two people, one of whom is the subject of the particular profile and then others could decide for themselves the degree of belief they personally choose to apply.
For completeness I might add that in some families, yDNA is confirming the understanding of principal lines and cadet branches. I am now using yDNA to rebuild the wider Sutherland family with yDNA providing positive proof of links which have long been suspected but rarely for which written "proof" exists.