Sounds reasonable. FWIIW, a couple of years back, I wanted to put a
deck on the back of my house. Needed it close to the ground -- maybe
12" off, at most, as doors on to it were just above ground level/one
step. I put in 4"x4" posts about 36" deep, resting on concrete pads.
Then filled with dirt. Cut posts off to desired height, and using deck
hangers, built a grid of 2' x 4' stringers, and decked this over.
Local code (Lancaster, PA) required holes to be 36" or more deep, and
on concrete pads. Glad I did, as a year or so later, I put a hot tub
on the deck, added a fence, and I needed the load bearing capabilities.