I think a classic example of what you allude to is Midsomer Murders which has gone from one extreme to another after the row about hardly any Black characters being featured.
It is set in an English Rural Village type environment in which very few if any Black people live.
However every episode now features a significant number of Black or Asian characters that simply wouldn't be found in this sort of rural location.
The writers are transferring multi-cultural populations from London where they probably reside to the English Countryside which looks ridiculous and appears to be tokenism.
I actually think that this kind of tokenism is not only box ticking, but actually makes things worse because it trivialises the issue of tolerance. Developing a society that is tolerant to people of all diversities will not come around by simply insisting on implanting, and emphasising characters into stories simply to avoid any complaints from the watchdogs, which is exactly what happens in those kind of television programmes. It needs to be organic, so like you say trying to represent all cultures in the setting of a small, rural village (with a frighteningly high crime rate BTW!) just looks ridiculous, and I'm sorry to say feeds the bias of people less tolerant. That's not to say writers should never include anyone not seen as typical rural village stock, but give them a story, help the viewers understand and empathise with them.
Its a really fine to balance on, push diversity too far and people will (and do) push back. Don't include enough and you further marginalise people. Having lived in one of Britain's most multi-cultural cities for most of my life, one thing I have learned is to try never to label people but to simply treat them as equal, although I must confess I don't always succeed. Labels are for clothes, not for humans. We shouldn't need to identify as one cultural / sexual / neurological / religious group or another, we should simply be able to identify as being a person with our own personal traits. There should not be a need to justify your background, your personal beliefs, sexual preferences, religious beliefs, how we think & perceive the world, what we choose to eat, or any other human trait. I honestly believe that this current need to identify is actually making things worse, we should be teaching people to simply accept people for who they are, so long as that doesn't hurt anyone else.
And this is all entirely possible, because I see it all the time when out walking. For some reason people walking along rivers, canals, through woods or on top of moors seem to just be able to greet each other with a warm smile & a hearty greeting more often than not, regardless of race or sexuality. I like to think this is a solid starting point for our species to move forward to just being tolerant to each other.