The genealogical chart is of descendants of Alexander (b 1720) who I think was Robert’s second son and probably the uncle of William (b 1776). Alexander was a dealer in Scotch linens. Although their name was often spelt “Sheddon” the records in Lewins Mead Burial Ground, Brunswick Square, suggests that, like the\Dudley Sheddens, the Bristol Sheddens belonged to a nonconformist Christian sect.
I cannot bridge the gap between the Sheddens/Sheddons in the chart and those later ones appearing in the Statutory Records for Bristol and environs. Also, from Census and other data it seems likely that several descendants moved to London, particularly to Shoreditch, where a large number of Shedden births, marriages and deaths are registered.