When using the "Managed by Specific Collaborator" view in the merge center, the list of names is displayed according to most recent login. That makes it very difficult to find who you're looking for, especially if you have hundreds of collaborators.
Please revise it so that it's alphabetical by first name. (I suggest first because that's more constant than surname, depending on culture, and it's the part of someone's name they'll usually leave in their display name even if they remove the rest.)