It would be useful to have a completion criteria option that allowed for "Any X number of selected activities" to award a badge. 

For example, we have a module that would like to have 10 quizzes, and award a badge if any 8 of those quizzes were completed.

With the current "Any" or "All" options, this isn't possible, and though it can be set up against gradebook, it's not straightforward and introduces too many complications.