I've worked some years ago in an office in Luxembourg. There were some german speaking persons working with the german version of ArchiCAD, and some french speaking persons working with the french version. It was a really mess. (But on the other hand: in the plans, there was some text written in french, and in the same plan, there was some text in german. In Luxembourg, you became very flexible in languages...)
For Switzerland, i know there were some very unique standards for layers, fills, zones, measures etc. from the SIA (swiss organization of architects). I think, this is the reason wy the versions are different in each country