Formatting applies to only the top-most fields in the viz. In this case, the fields are [Ranking # or %] and [Score # or %]. You can't conditionally format these fields, unless you mess with the output. For example:
case [% or #]
when "#" then STR(SUM([Ranking]))
when "%" then STR(SUM([Ranking %]) * 100) + '%'
There are a bunch of ideas about conditional formatting, I encourage you to vote up the appropriate ideas. Here is one that you may like: https://community.tableau.com/ideas/1411