The promise that the ecosystem would manage itself and wolves would just pick the least fit of the herd. It's shown they just like to kill for the thrill. There are cases of 30 sheeps per night in one site. 'Just Place fences' is a common heard thing, however wolves are smart and will just jump over or dig underneath. If you want to make a proper barrier with concrete is just practically unaffordable for the farmers.
Sounds like yall should implement something like this
https://www.fws.gov/service/wolf-livestock-loss-demonstratio...
Although a quick googling appears to show that there is a compensation scheme in place for livestock killed by wolves, although I see a lot of commentary on it being insufficient.
Livestock guardian dogs and other methods are common around the world where predators still exist in the environment. Why can't the Dutch use them?