I'm guessing you think it's nonsense because there's a fundamental lack of understanding on your behalf, i assumed such a simple notion wouldn't need explaining but i guess i overestimated.
Major cities would be places like London, Cardiff, Manchester, etc, etc. Rural areas and smaller towns would be located outside of those major cities, Cardiff would have it's own rural areas and smaller towns, Manchester the same, etc, etc. A rural area or smaller town is geographically associated with the city that it's part of, you don't say a rural area or smaller town outside of Cardiff is a rural area or smaller town of London and visa versa. It didn't think a place being associated with the place it actually exists in would be that complex, i would've thought that when someone mentions the rural areas or smaller towns of Cardiff they mean Cardiff and not some place 150 miles away.
Your second attempt further reinforces that, he travelled from Cardiff to 20 miles past Port Talbot. He was from Birmingham, he did not travel from Birmingham, at least not on the day he was arrested and one would assume from this statement..."Edwards has significant history for possessing drugs with intent to supply, along with violent offences including stabbings and robberies in Cardiff." that he's resided in Cardiff for quiet sometime.