I suggest you also read https://www.geni.com/projects/Descents-from-Antiquity/12283 somewhere you tree needs some cutting.
Polly GEDmatch kit # TA7057982 it's not my area of expertise.
I looked at the path between yourself and #22 pretty much right in the middle is Janet Scott
#1 her name "NN" is a latin abbreviation used by genealogists to mean name unknown.
#2 she has no dates.
#3 the only data in her profile is a hyperlink to the Scots Peerage
#4 the Scots Peerage states: "-, a daughter, married to ... but no evidence is forthcoming."
So there's a link that immediately screams CUT HERE! Someone has created a wife for David Scott and used her to link him to the Lords Sommerville without any actual evidence. This kind of thing has happened constantly throughout history. Unfortunately once you cut NN's link to her supposed parents you'll quite likely just get another path to #22 as the whole aristocracy is an interwoven web of marriages and this example of a false link that i've managed to find is a very obvious one which even I could spot others will be much less obvious.
The best advice I can give you is to walk the path starting from your own profile checking for evidence each step of the way, it's hard work. If you need help cutting a connection I will be happy to assist but finding which connections to cut doesn't interest me. If you find a link which you think is fake but you aren't sure try starting a discussion from that profile and you might get feedback from the other managers.