Cardiff yeap though the English will be moaning soon if one isn't named after a "British" city soon (and by that they mean English) I would suggest it could be London. But Cardiff to cover wales. Then a northern, Midland and Southern English city.
So Newcastle, Birmingham and London with Glasgow, Cardiff and Belfast.
well the naming of the first three is a shameless and pathetic attempt to tie the nationalistic sentiments of the provinces to the Royal Navy. They aren't going to give any special attention to the North, because why would they?
For all of their bitching the Scottish don't actually know what it's like when Westminster really doesn't give a fuck about you.
however the political motivations of the politicians aside, they're perfectly serviceable names with long histories, as to what the other 3 will be called
Coventry, London, and if their whining manages to have any effect, Portsmouth