I trust your research, but I wonder if technically there will be problems in retaining Thomas and Edward as brothers, if they are delinked from John Batten. I know if you create siblings, the system automatically creates a profile for the father.
Is it possible to delink the profile for John Batten from the profile for his father, and then rename John to Unknown? That way you can still retain Thomas and Edward Batten as brothers, but make it clear that their father's name is Unknown.
Or is there doubt about Thomas and Edward being brothers?