The Guardians are my creation where the League of Champions are the original hero group introduce in Champions, Giant, Flare, Marksman and such.
The Watchers if Avalon is quite different from Circle. The group is neither good or bad and rarely takes sides, though individual members may, in the conflicts in a super's world. They merely watch over this dimension and protect it from the forces of other dimensions using the forces of this world to do so.