Uh, no. lol That was true a couple years ago. :) There's been alot more testing.
You are breaking off into your own branch here: FGC10125 > FGC10113 > FT88711
The bulk of Campbell (at least those that share an ancestor with the progenitors of the name) breaks off here; FGC10125 > FGC10113 > FGC10116
Btw, is your MDKA John Griggs? 1750-1819?
I have two Griggs kits already listed in your haplogroup.
Your "brother" branch is so far occupied by SInclairs from Lybster (a particular branchof theirs it seems...they likely took the name)
There's no one listed at your "parent" branch at the moment...however the parents "brother" is home to the McFie/MacAfee/McDuffy chiefly line...this is going all the way back to an estimated 1000 CE...for the common between the two branches...You could think of them as your cousins since both branches broke off the "parent" about the same time... So they are even closer than Campbell...
The "parent" they broke off of is one of four "brothers", a;ll sons of FGC10113;
FGC10116 - Campbell, the largest branch of course, shrug
FT365813 - Mixture of McClain and Macintosh, very small
FT88711 - Appears to be MacAfee/McDuffy/McFie chiefly
FT259334 - Contain the Urquhart chiefly line, although that is not reflected here at Wikitree for who knows why? And an Alexander branch, could be name changers?
Here were probably looking at around 500-700 CE or so time frame, just before the Viking era if I recall...
These four seem to be following Robin Spencers Power Law (the large get larger)...The other three are about the same size to date...Hard to draw any conclusions from that though...maybe you all just don't like genetics? lol
Anyway, your Griggs branch seesm to have a recnt dating of about 1900 CE...where the two Sinclairs are stimated about 1600 CE (FTDNA's "best guess"). They call them the "Exeter" (NH) branch... I imagine your line were Sinclair (this particular branch, most Sinclairs are in a completely different branch if I recall)...for quite some time after breaking from MacAfee/McDuffy....
ersonal;ly I think McDuffy is a major clue as the Gaelic for that is rooted in Dubh, which I think means "black". The Campbells have quite a few ancestors with that as part of their nicknames...Black Duncan of Glenorchy..more than one Ian Dubh. Ian Dow, etc...If I remember its pronounced like "dov" but with e "v" aspirated...Ah, here it is...
https://www.youtube.com/watch?v=ALDg2zWOdvQ
I better quit there before I get in any more trouble...lol