Hi
In what context did you come across the name ATCHAM? The reason I ask is that its not uncommon to find the same name used for different entities. If you are referring to a birth certificate then the Civil Registration District of ATCHAM straddles the boundaries of the counties of Montgomeryshire and Shropshire. The link below gives details of its coverage and you will see that it includes ALBERBURY and CRIGGION.
The Church Parish of ATCHAM is only one of many parishes within the Civil Registration District of ATCHAM.
http://www.ukbmd.org.uk/genuki/reg/districts/atcham.htmlThe Church Parish of CRIGGION/CRUGION was formed in 1864 out of the Parish of ALBERBURY (see link below) prior to that it was a Chapelry in the Parish of ALBERBURY (see link below)
http://www.genuki.org.uk/big/wal/MGY/Crugion/index.htmlhttp://www.genuki.org.uk/big/wal/MGY/Alberbury/index.htmlThe border between England and Wales is not like usual national borders in that often the only indication is likely to be a sign on a road saying Welcome to Wales. Whilst in some cases the border follows a natural boundary such as a river in many cases there doesn't appear to be a logical reason for the border. It cuts through parishes and I believe in a few cases, farms. In one place in North Wales, houses on one side of the road are in Wales, and the houses on the other side of the road, England.
As people quite often moved about it is possible that if a parish or locality straddled the border that family members could be born in different countries but use the same actual name. The parish records may have actual addresses that might help show the exact locations.
The parish links above do give some information regarding the locations of the parish registers.
Andy