Hmmm, I haven't found it to be true that Germans and Dutch people speak English equally well. There really is a pronounced difference, especially in the older generations, but also in younger generations. I speak German when in Germany, so of course I have some bias, but there is evidence to back this up [1].
As for how intentional it is, your theory seems plausible. That said, I don't know of any real evidence for it — even if it is an organized conspiracy, most normal Dutch citizens aren't aware of it.
As for how intentional it is, your theory seems plausible. That said, I don't know of any real evidence for it — even if it is an organized conspiracy, most normal Dutch citizens aren't aware of it.
[1]: https://www.wittenborg.eu/netherlands-top-english-speaking-c...