Belgium's minimum limit is a third of surrounding countries. So 4 times the legal limit would only be 33% above the legal minimum limit in the Netherlands and Germany.

The minimum limit doesn't imply any sort of intoxication though. It is the amount where usage of the drug becomes proven in a legal context. This of course means that none of these drug tests prove driving while intoxicated as you can easily get a positive test while being sober.

I personally already had multiple positive tests while driving sober. It's an awful system that punishes drug users for their drug use and not for any DUI. The fact that they focus more on the test than actually talking about stuff like his speech and mental state when police arrived on the scene shows a lot. They just want to punish the guy as hard as possible and make him look like a criminal.