Just found a new toy at GEDMatch, not sure how long it has been there, but it is labelled as "new".
THAT is a pictorial representation of which of the atDNA tested descendants of Archibald HENDERSON and Margaret McEWAN who have uploaded their raw data file(s) from their test to GEDMatch, have matches to each other.
(Archibald and Margaret married in1804 at Stirling, Archibald being one of my brickwalls.)
The associated data and generational estimates between the matches are shown on the DNASurnames HENDERSON FamilyFinder page.
Other than being a pretty picture, the generation estimate table very quickly shows the randomness of atDNA inheritance and how many of the descendants shown did not inherit any significantly sized segments from Archibald & Margaret that also matched another tested descendant.
Now if the others tested would only upload to GEDmatch as well, we'd have a more complete picture - as well an ability to place several more of our matches who tested at other companies, or come in below the FamilyTreeDNA thresholds.