I was going through my badge collection and when clicking on my badges, I noticed that my rare badges of Mentor (earned by 0.29% of Exercism users) and #12in23 Participant (0.53%) are percentage-wise rarer than my ultimate badges Conceptual (1.46%) and Contributor (1.66%).
However, the ultimate badges seem to be of a higher value than rare badges - I thought this partly because of the color scheme and the below wording: ultimate badges come before rare badges, which I interpreted to mean that ultimate badges are better than rare badges. This wording is the same in other ocassions.
@ErikSchierboom Given that Growth Mindset is marked as common and Contributor as ultimate, one might expect that the latter is rarer than the former. However, 13229 people have earned Contributor and only 8544 have earned Growth Mindset.