There aren't many people who apply for, or get a watch managers job without knowing what is expected of them, as appears to be the case with FSW1.
Personally, I wouldn't mind having a crack at watch management but I've no real desire to go any further than that, I could still plug in despite the other duties and not have to commit myself to losing too much time off whilst getting a pay rise commensurate with the post.
Some people can handle the transition, some can't, but it's no secret that when you're an ordinary ATCO you can always do the manager's job better than they can.