While a pole is a structure, there is a section 225.32 ex 3 says a disconnect is not required if located elsewhere. Otherwise every lighting pole would be required to have a disconnect.
As for a ground rod, there is no reason to have one other than designers don't like to change there drawings and thats the ways its always been done.
Gotta be the single lamest excuse for a definition in the entire set! "That which is built or constructed." I built a kite in my youth. I once constructed an argument in favor of legalizing tap water. Sheesh! :roll: