Silkeborg 's hills are longer but the gradients are mild and the roads are often wide. You will find a lot of Poggio-esque climbs in that era.You would think that, but the only really great rider to come out of Vejle is Tony Rominger
The area around Silkeborg seems to be a much better training ground, judged by the number of good pros coming from there.
Those in Vejle are short but really nasty. And there are enough of them to make a really hard WT classics without using the same climbs as a loop.
The problem will the same as in Amstel.. there are exceptionally many bumps, tunnels, railway crossings, traffics islands, bollards, narrow paths and annoying obstacles in that area. I'm not sure it's safe for a full pro-peloton.