Beautiful garden! Great job on your first grow.
I would say if you want to avoid back issues (I know, I'm right there with ya brother), and still have the same # of plants, work out of smaller tents, say a 2 x 4 so you have one row of two or three plants easily reachable. I'm thinking you could easily get 9 plants in 3 - 2 x 4 tents. You would most likely still need to kneel down to take care of them.
If you wanted to sacrifice a plant or two in the same 5 x 9 tent, do less plants and you will have more space to move around and amongst the plants. If you were a little skilled, you could cut out access doors on your big tent on the sides where there are none. Couldn't tell from your photos if each side has its own access, but that is a must have on those larger tents and make it a real pain to do even basic watering to the rows in the back without multiple access doors. Same as above, you would most likely still need to kneel down to take care of them.
The scrog limits you and how much you can move the plants around if you go that method. If you want to move them in and out of the tent to put them up on a table to avoid bending down, you could rig up some sort of tomato cage or personal scrog net over each pot or use stakes to support your branches and flowers. As long as you keep them short, that should work too.
5x9 tent
