It's definitely not a unique case. There are loads of multi-lingual families in Europe, especially in polyglot cities like London (not to mention polyglot countries like Switzerland with FOUR official languages). It's a perfectly normal use case that my wife would want to buy Italian-language content from the Italian iTunes store and that I would want to buy English-language content from the UK iTunes store to share with our (bi-lingual) daughter to watch on our Apple TV via "Family Sharing".
I bet there are loads of English-Spanish bi-lingual families in the USA too, no?
Here here! - most definitely not unique... mine is a multi-lingual household, I am English & have a UK based Apple ID, which I have had for years, setup back when I genuinely did live in the UK... Now I live in Norway, my Wife is Norwegian, and she has her own Apple ID (obviously she needs this as she has her own iPhone & iPad etc.). Her Apple ID is Norway based, - quite correctly... We have both had our own Apple ID's for years, and have loads of purchased content individually, so would frequently switch between our ID's on our Apple TV (gen 3), which was a reasonably seamless experience... Having just 'upgraded' that to the new Apple TV gen 4, I am quite dismayed to see they have changed the way ATV handles multiple accounts, such that AFAICT, there is no longer a way to have it store & remember the details of 2 Apple IDs, and allow quick selection & switching between them... it seems like it now relies on Family sharing.... - which we cannot setup between our ID's...
Backwards step... :-(
Now, whenever we want to switch to my wife's Norwegian AppleID, we have to go through the tedious process of "adding" it again from scratch, slowly pecking out the account credentials one character at a time...
THIS IS NOT "APPLE" USER-FRIENDLY!!