Take the sq footage and divide by 2.5... if you have that many level, ready-to-go-vertical colas, you are good to go. there is such a thing as too many mouths to feed and it is a function of numerous factors - light and other environmental variables, pot size, growing method, fertilization choices etc...
too many colas will produce a higher proportion of larf. too few will be light on potential yield. 2.5 colas per sq foot, give or take, should do you well. A little less is fine. i like it to be even numbers reltiave to topping X times. as long as the canopy fits together, it doesn't have to be symmetrical per plant. a little jig saw puzzle sometimes is best.