Umm, that doesn't sound much like England. Here class still beats race in most social interactions, IME.
England would be the exception I can think of, because England has retained so much tradition from earlier political times. For instance they still obviously have a monarchy, even if it is just a figurehead in most respects.
From the Englishmen I know I would say though that class has become over time more and more a social affair rather than an overtly political and cultural one, that is in some respects England goes out of her way to want to appear "democratic." But from my experience it is still both the society most like the United States culturally, and in many respects very much unlike the US culturally. So you've got a good point. Things vary even when they change.
I think PP and Cele and others also brought up good points about cultural, political, societal, and religious conditions.
But one thing I have definitely noticed in game design is a general lack of mechanisms for change over time. As different cultures, races, religions, societies interact in the real world there is always change and alteration. Societies become more and more like each other in many respects but with many retaining the peculiar quirks of their historical background. As has already been discussed. In other respects though societies undergo huge change and modification through exposure to other cultures, religions, societies, institutions, and so forth.
I'm working on writing a game right now for the Conjunction contest that will address those problems in gaming. Because most games and settings tend to view milieu as basically static and unchanging. That is to say that once setting is established and cultures written out they tend to remain the same from then on, varying only in particulars like who is the individual ruler, etc. But in the real world whole societies, political structures, cultures, languages, ethnic groups and races, technologies, etc. undergo dramatic change. I am generalizing of course, but generally speaking, in-game, things remain static, unchanging, and boring by comparison.
For instance the church of today is not the church of early Christianity or medieval Christianity. Kings of the late medieval eras are not the same as kings of the early medieval eras. Technology varied widely over different time spans. Those societies that took place in the Crusades and Jihad became very different, over time, by being exposed to each other, to Judaism, and to other Near Eastern and African cultures than they would have been had they remained isolated from each other. Trade made a big difference in changing societies and even cultures.
In games where you have a setting that is basically static, and where there is little cross-cultural, inter-religious, and economic interaction then societies would be basically unchanging over time. But in settings and games where there is specific and intentional interaction between different societies, cultures, nation-states, economies, religions, and so forth there needs to be a built-in game mechanism for change. Both distinct change and wholesale change. World change even.
And not just cultural change. Professions would likewise change over time as societies and individuals do.
The early Knight is a very different thing than the later Knight. The cleric, if he could be called that, of the catacomb Christians was in some respects a totally different creature than the cleric of the high church right before the Renaissance.
So there need to be in-game mechanisms for change. For cultural change. Religious, societal, political, economic, professional. In my opinion it would make the game much, much, much more interesting.