I'm sure one of them even had a Welsh accent :o
I need to hear this. There arent enough Welsh accents in games. (Play The Unwritten Tales)
Also others may have pointed out...
What is this 'British' accent?
The UK has a very large and diverse amount of accents varying upon region. So as someone who lives in the
UK the voices sound varied.
Also: Gale's voice definitely comes from the UK too.
Using the same shortened versions of words, similar tones, substituting various phrases/words for things like insults (bloody, bollocks, etc.). And you actually make a fantastic argument for there being more than just British accents in the game. Even within a typical Accent there are numerous dialects that can add even greater diversity. For example, if all Tieflings are going to have a British accent, you can then introduce various other dialects for different characters (Welsh, Cockney, etc). The Tiefling merchant can sound similar, but still distinct from the rapscallion child, who can sound different from the more sinister servants of a certain devil.
While certainly a trope, Dwarves sounding Scottish can have the same diversity even within the Accent itself. I don't know enough about linguistics, but I'm willing to bet the overwhelming amount of accents you could pick from could have tremendous diversity within them, providing for an even more immersive experience!