Birds of a Feather question

I am an English person living in America. I love Orlagh Cassidy's narration of the Maisie Dobbs books. Until I researched her I did not even realize she was not English herself. I think she 'does the voices' really well and I very much enjoy listening to the books, which are among my favorites. I understand that the narrators are the decisions of the publishers rather than the author, so my question/comment here is aimed at those 'in the know.' I am curious...
Who decides on pronunciation of place names and - let's call them - brands? In Birds of a Feather, Dulwich, London is pronounced dull-witch. Any English person knows it should be pronounced dull-itch with a silent w. Hovis bread is ubiquitous in the UK. Again, we all know it is pronounced Hoe-viss (like a garden hoe) not hoh-viss with a short vowel o. Who's job is it to check things like this? Brits pronounce a horse's paddock as a pad-uck, not a pad-ock with a pronounced o like in flock (of sheep). And what's with the long vowel sounds for words like 'gas'? I've never in my life heard anyone, from any part of England, talk about a garce stove instead of a gas (pronounced gass) stove. There are many, many examples of these weird words with a in them, in the two Maisie dobbs books I've listened to so far. And I 'm not talking about words like grass and bath here, which I pronounce one way and my husband another as we come from the north west and London respectively. I'm talking about general words with a as a short vowel and not a long vowel.
So who makes these decisions? Who doesn't notice mistakes like the Dulwich one and lets them through. I am so interested to hear from other 'listeners' who notice things like this. Thoughts?