The tags lists are sorted by votes (descending) and name (ascending).
But (for artists at least) name is the standard name and not the sort name, so it is sorted by first name rather than by surname.
Here is an extract from the Classical tag Artist list:
2 - Dimitri Mitropoulos (conductor)
2 - Domenico Scarlatti (composer)
2 - Dubravka Tomšič (pianist)
2 - Ebe Stignani (mezzo soprano)
2 - Edita Gruberová (soprano)
2 - Edvard Grieg (composer)
So Grieg comes after Gruberova comes after Scarlatti.
I suggest that the list should use the sort-name instead of the name.