Blm is a bit special in this rating because you need a half decent team or you worth nothing, but if you are in a half decent team, you can clearly more carry than a smn. Plus it put a higher pressure than smn: You can't really let him free cast... But you can't let free cast the healer too, which creat really annoying situation in solo queue.
The more I play smn, the more I think it was down to low tier (in terme of solo queue) because I m completly incapable to carry something now when it was easy to carry with the higher burst (well obviously).
