Ah, the Dean(e)s of Taunton once again...
It's useful to know that most of Taunton's early records were lost, so what "records" we have today often were reconstructed (long ago) from family bibles, etc. -- and there are many gaps.
Unfortunately, R.B., who posted much of the earlier analysis of the Deans, is no longer a member of WikiTree, so we cannot rely on his expertise.
I was another major participant in the earlier discussion (I have at least one Taunton ancestor named Dean). I've not revisited the sources today, but my memory was jogged by re-reading the various profiles and the earlier G2G. It was clear to me at the time that John Dean didn't have a daughter Lydia. Also, after the daughters of his brother Walter Deane were identified by various means, there were no unidentified daughters left who could correspond to Lydia (Dean) Hall.
But Taunton was a pretty small community in those years, so there wasn't an infinite supply of Deans. Since Thomas Deane of Taunton left a will that mentioned a daughter named Lidiah, and the Hall genealogy identifies her as the Lydia Dean who married George Hall, I think it's entirely reasonable to conclude that Lydia Dean was the daughter of Thomas and married George Hall. So I endorse your proposal to disconnect Dean-625 from Walter Deane and Eleanor Cogan as parents, then merge Lydia Dean-625 into Lydia (Dean-324) Hall, daughter of Thomas.