Hey Michele!
Sounds interesting.
OK - so, fill in a few details here for me please. Do you already know how you descend from Matthew Patten? For me, knowing my relationship to an ancestor is critical when trying to use DNA evidence in support of a relationship.
Here is an example from my research. Long story short, I am trying to determine if my gr-gr-gr-grandfather, John J. Coates (1815-1867) is related to Jeremiah Coates (1817-1896). John lived in Meigs County, Ohio, while Jeremiah lived in Gallia County, Ohio. Meigs and Gallia are adjacent on the map.
I don't have any paper documentation that strongly supports their relationship, but looking at the information from census records, etc. makes a relationship (perhaps they were siblings - or perhaps first cousins?) seem plausible. Fortunately, there is some interesting DNA evidence to consider.
I have 8 tests (on Ancestry DNA that have been uploaded to Gedmatch.com) from descendants of John J. Coates who match one another (the 8 tests are first cousins, second cousins, and second cousins - 1 X removed to one another) and 2 tests (Ancestry DNA uploaded to Gedmatch) from descendants of Jeremiah Coates (the two testers are third cousins). Just looking at the respective family trees of the 8 tests, John's descendants would be 4th cousins of Jeremiah's descendants if John and Jeremiah were siblings (and 5th cousins if John and Jeremiah were first cousins).
Similar to what you can do on FTDNA, I have run one-to-one comparisons between each of the 8 tests from John's descendants to each of the 2 tests from Jeremiah's descendants. From this, I see that 5 of the 8 tests from John's descendants match Jeremiah's descendant, RKH, and 5 of the 8 tests from John's descendants match Jeremiah's descendant, Duane. Looking at these basic comparisons, I can identify 10 different DNA segments that exist between a descendant(s) of John and a descendant(s) of Jeremiah.
Taking this to the next level, I then ran a 3D chromosome browser comparison for the 10 tests. From this, you then see that, in 4 of the 10 DNA segments, two of the descendants of John share the same segment with one of the descendants of Jeremiah. Arguably, these 4 segments are "triangulated" in that two separate descendants of John share the same DNA segment with one another AND with one of the descendants of Jeremiah (i.e. triangulated across three independent testers).
I was hoping that the two descendants of Jeremiah would share segments in common with one or more of the descendants of John, as this would be very strong evidence of a relationship between John and Jeremiah. My current data did not produce this result. But, since I only have 2 tests from Jeremiah's descendants, my next step is to add additional tests from descendants of Jeremiah.
So - this is an example of triangulation. I am using DNA evidence from multiple descendants of ancestors to explore a relevant genealogical focus.