You really do not need a VL for this.
In the Tag Browser each Author (Series,Publisher) has a count next to their name
In addition, If you use the 'Alter Tag Browser" (or your locale name) button at the bottom of the Tag Browser. Set it to: 'Sort by number of books' and the 'Authors' list will now blocks of numbers (descending)

If you see the same range more than once, you have a 'Partition Rule' that breaks them up. This is not a
problem.