I must thank you again for the interesting & enlightening information you have shared.
I fully appreciate your reluctance to speculate as to where both Humphrey & James Atherton may have been born in England. As you say, theories abound and also conflict with one another.
I suspect that the underlying problem is the shortage of reliable information available to people in the USA that can be sourced via the internet.The Atherton Manuscript Collection has three files on Billinge & Winstanley, none of which is on the net. There are 50 or so Court Rolls naming Atherton's in the Billinge/Winstanley area but again, none of this is on the net. Turning to church records during the 17th century, most of these are Church of England records but not even all of these are to be found on the internet. As to minority religeous groups, I do not believe there are any records on the net that cover this area during the first half of the 17th century.
However, turning to Humphrey Atherton of Winstanley there is not one atom of doubt that he is the son of Edmund & Elizabeth and the grandchild of Humphrey & Alice Atherton.
Humphrey (1607) is recorded as follows-
1/ In the baptism register of Upholland in 1607 2/ In the will of his father who died in 1613 which also names his mother, his sisters, cousin Richard Atherton and his mothers brother Roger Molyneux. 3/ In the Inquest into his fathers estate which confirms Humphrey as his fathers son and heir to such land as his father had held in perpituity (Socage). This inquest does not concern itself with Edmunds other lands & assets.
As to Edmund Atherton he is recorded so-
In 1595 Humphreys grandfather seals a deed for the transfer of Romeshaw House and for the avoidance of any future dispute the deed is counter signed by Alice Atherton, wife and Edmund Atherton, son & heir.
However, though Humphrey of Winstanley is well recorded it does not mean that he and Humphrey of Dorchester are one of the same. But the Winstanley Humphrey drops of the radar during the first half of the 17th century and is not named in later records which name his sisters! I expect that you are aware of the short cameo study of Humphrey Atherton of Winstanley that I drafted for an Atherton web site.
I know that your friend Carol has a significant interest in James Atherton. Atherton is a common surname (its a place name) in South West Lancashire and the Parish of Wigan is close to the epicentre of that surname. But whoever James Atherton was, he does not appear to have been a sibling of Humphrey of Winstanley.
The next nearest clan group of Atherton's lived in Ashton in Makerfield in the Parish of Winwick.During the early 17th century these people evidence a preference for Roman Catholic worship and this impacts on their recording in Winwick Parish Church.Some of this group moved to Bold in the Parish of Prescot which only serves to complecate matters. The Atherton's of Ashton & Bold are my ancestors.
You have been very kind in sharing your knowledge and if you friend Carol wishes, I will search for a James born in the early 17th century. Humphrey of Winstanley had an uncle and aunt named James & Anne which would be a starting point.