Yes I didn't say everyone should use the same language, just that a lot of things would be much easier if that was the case.
But more and more is in English these days even if you're not in an English speaking country. More and more local companies here has English as official corporate language.
Just about every book used at engineering colleges here is in English. Except for mechanical engineers who I'm told also use a lot of German material, probably because of the long history of a big steel industry in Germany, and because most Danes learn both English and German in school.
It's too expensive to translate and maintain most technical literature to a tiny market like Denmark, so almost all technical literature used here is in English, usually books from American authors.
But enough about that.
Regarding sourcing rare transistors etc., since the Internet became widespread it has become much easier to find Japanese and American transistors here and other even more exotic parts. Before the Internet it could be very hard to even find a datasheet for some transistors, so it was very hard to even have a chance to find an equivalent part. The small yellow semiconductor database books from ECA was very popular back then, to find data and equivalent parts:
http://eca.deBut now you can find most of the needed info on the Internet and order most parts from around the world online at eBay, AliExpress, Mouser DigiKey etc. if you can't find it locally.