[NeoTar]

I suspect they all could be British English, since the variations are less pronounced that one might think:

re: Focused - to quote Wiktionary:

"The spelling focused is much more common in the US but also more common in the UK and Australia. The Oxford English Dictionary describes the spelling focussed as irregular."

Speaking a native British English speaker, I'd agree. I focused looks OK, but focussed looks weird to me.

Prioritization:

The 's' versus 'z' debate is perhaps a little more complicated than often presented. There are some words which always were historically spelt with a 'z', but since the interpretation that 'z' is American have started to be spelt with an 's' in English.

In particular the OED (Oxford English Dictionary) tends to favour 'z' spellings for a number of words over the 's' spellings - I think 'nationalization' is a particular example.

[smitty1e]

At least they did not wax Germanic with "focuß".

One can always cheer a bit of optimization like merging 'ss' to 'ß'. In the spirit of the thread, though, stopping at just the one seems odd.