Well my 13 year old 16hh, QH is very laid back and easy going, but on trails he's hypt up and always in the lead! So 3 to 8 depending on the day.
My moms 3 year old 14+hh, little Paint mustang has SO much energy so he's 9 or 10 but after a bit of riding I can get him to come down and really listen and he still has engery for when its time to go!!
My 5 year old TB/paint is about a 5 and can go but doesnt always want to. But super sweet and loved to walk.