I don't quite understand what you mean by "tracking". Speaking of Germany, because you mentioned the Abitur. Yes your ability to enter certain universities and studies depends on your performance during the Abitur. That is to enter e.g. law or medicine at you chosen university immediately (there is a wait time multiplier, so you can wait if you don't get in immediately) requires a certain grade point average. However I don't understand how this is different from SAT scores in the US (except for maybe the ability to bypass SAT requirements by being super wealthy, but I'm not sure that would be a good thing). In my experience kids in the US tend to be obsessed about their university choices much earlier than the ones in Europe.

Also talking about Germany, unless things changed dramatically in the last few years, most natural sciences and engineering degrees don't require a grade point average.