I think we can all agree that there should be a relation between the badges to indicate their significance, one such relation is the
color (gold > silver > bronze) that is already implemented.
It's only natural for the
shape to also constitute an indication of each badge's significance.
However the current badge shapes (lozenge > circle > triangle) do not follow any logical pattern.
I think it would make a lot more sense to associate the significance of a badge to its complexity in terms of how many edges the shape has.
Which results in the following (lozenge > triangle > circle) instead: