I have a set of marriage and baptism records for an 18th century/early 19th century English parish, and want to assess the probability that the participants are related in some way, before I spend hours and days tracking all mentions of the surnames in the relevant (and adjacent) parish records. If they're common surnames in the area at the time, it's probably wasted effort.
I know there are resources that look at the frequency of surnames in the 19th century censuses, but is there anything earlier?
My data (so far) (all sources from the Rowley Regis Parish registers published by Midlands Ancestors except where noted).
Daniel Nightingale married Sarah Raybould 15 Jun 1777 Brierly Hill(Familysearch.org)
Daniel Nightingale (son of Daniel above) bapt 1789 married Mary ? 25 Dec 1812 Rowley Regis
Richard Nightingale (son of Daniel above) bapt 1814 married Mary Darby (bapt 1813) 10 Aug 1834 (Halesowen parish registers from Midlands Ancestors)
John Jones married Mary Darby 27 Sept 1733 Rowley Regis
Hannah Jones (daur of above John Jones) bapt 7 Aug 1734 Rowley Regis) married Joseph Nightingale 16 Oct 1758 Rowley Regis
Johanna Nightingale (daur of above Joseph Nightingale and Hannah Jones) bapt 15 Apr 1770 married Isaac Darby 26 Aug 1804. These were the parents of Mary Darby (bapt 1813) who married Richard Nightingale above.
The Darby link is visible (but where does Isaac Darby fit in?) And how can I determine if the Nightingales are likely to be related?