What? There have been 9 editions of the Gold Race with the Cauberg finish, that has resulted in a 'bunch' sprint twice, a sprint of a medium sized group twice, once it resulted in two guys who escaped before the Cauberg sprinting, once in a group of three guys who escaped before the Cauberg sprinting, and three times it ended in a succesfull solo. Getting away before the Cauberg has a succes rate of 55%, not 10...
I do think you're overestimating the course a little bit, I think it could be a bit easier than the Gold Race, but then again a WC is raced differently as well. That scenario you descride is certainly a possibility, that's the way Vinokourov, Schleck and Schumacher won the Amstel.