If its 27"x27" as you mentioned last night then you can do 25 pots. But yeah around 16 would be safe.
If you’re running these small pots you might wanna look into auto watering options. Flood and drain would work great in a 2x2 a few OGers have done it. Or even just a big tray that you can bottom feed from.
Good luck though, I have a 2.5x2.5 closet and I had a hard time running 6 autos in the 3 inch pots… hehe