you could throw less than 1/3 and still throw more overall. That said our conversation here was really stretching the definition of “downfield” by defining it as any throw over 10 yards just to give Huntley the benefit of the doubt for purposes of the discussion.
I would bet most QBs are throwing 10 yards downfield more often than Huntley unless they play in a very run heavy offense. The percentages are only important in Huntley’s case because the overall number of passes he throws each game are so small comparatively. That skews stats.