They are Scottish beavers now. There is, in any case, no practical difference between Bavarian beavers and Norwegian beavers.
Beavers are the vital missing link in our ecosystem.
As we face climate change, the return of beavers is creating and will in time create much more biodiversity and more resilience in the countryside than any other single measure that could be contemplated.
Overall they help to reduce flooding. In places they cause problems. There are established and successful methods of dealing with such problems and breaking down their dams is not one of them.
You would do well to widen your research base beyond the gamekeeper fraternity.
Those who regard everything apart from a handful of favoured species as “vermin” are the sworn enemies of biodiversity.