I think i know what you mean. No, if you top the plant, the other colas will not be as big as the 'main stem' cola, but all the other branches will catch up with eachother, leaving you a nice flat canopy with more colas, by topping your plant you will keep the plant low, have more colas and get equal light (lumens), in other words, you will gain a bit more yield from a shorter plant.
I actually did this on acident..I was trimming a leaf a little too close and cut the top off the plant...After that 3 nice buds have grown up from that spot..