I think there would be cross ties at each stall, or tie rings to the rail of the arena, but yeah, it can get crowded and any width I can spare for aisleway would not be wasted!
And light is important. There would be lots of lights, but I also would have not only the windows above the stalls for daylighting, but skylights in the roof. I hate dark barns.
I've done the common tack room thing too, and hated it. stuff gets moved or borrowed, saddles get scratched, and I really like individual storage with a key.
It looks really nice. Have you been looking for property?
If you are going to be having camps you might want to think about a "classroom/lounge" area too. The owner here has a trailer for this. We also have a place where we can leave our trailers.