My Chadd line is Joseph Chadd 1743 & Jane Mould b 1745 in Bosbury, Herefordshire. I think they had 12 children - my direction ancester William and amonst the others Thomas b 1775 and Samuel 1787. I can only vouch for this information, having not researched William's siblings lines.
I went to Hereford Records Office recently and made a note of various Chadd baptisms. I did find a Samuel christened in Bosbury Dec 12th 1813 - parents Sherborne and Phoebe. Sherborne was another brother of Samuel, Thomas and ~William.
Although Samuel seems to be a family name on my Chadd tree I have not mention of either a David or Daniel.
Hope this is of some use to you and I do wish you the best of luck with your researches.
If I manage to get down to Hereford RO again I will keep a look out for the names you mention.
Sue