Well yes, most teams do pass on 3rd and long. However, Ive found it very beneficial to check what teams do on 1st and 10, 2nd and short, and 3rd and short to get a feel of what kind of offense they are running
If they skew towards the run on first down and x and short, then thats what i gameplan for
however if they are 50/50 on first down and heavy pass on 2nd and short then i gameplan against their qb
I dont think the ALL section of the gameplan is very useful, since there are just too many factors that go into their total play selection (they could be a run first team but without success at it they find themselves in 2nd and long and 3rd and long very often, which would mean their total numbers are pass centered but what happens on first down is what matters to me.)