I am not convinced that the Conservative party needed to do anything radical. I don't think their defeat in the last election was due to any great failure by the party so much as in being tired of Stephen Harper. I don't know anything about Andrew Scheer, but from what I'm reading it seems like he's a more media-friendly guy in the Harper mold, as opposed to a big change. That might be all they need.
A lot of people seem to think Trudeau is a rock star whose personal popularity will crush his opponents... but a lot of people see him as a lightweight who is all style and no substance. Perhaps right now Trudeau would clean up in the next election, but things change. If things don't go smoothly over the next couple of years, the rock-star persona might not be enough.
-k