if there are alot of tops.
meaning, they crowd eachother out.
then you are going to have reduced yield. because they dont give eachother the space they need.
small top, small bud. that goes too.
and light does not penetrate the leaves or buds to any extent. so all those buds are gonna shade eachother out and limit the good yield to the utmost top buds.
but say if you, got 10 tops, kept it that way,gave it adequate rootroom and time to size up those tops. youd get a lot more yield.
specially if those tops are spaced such that they pull eachother apart (easier achieved with 4 tops actually which is probably the best number to shoot for, number vs size type of thing)
giving light to the plant.
problem?
you need alot of time to veg that plant out to give you big nice buds on it. shorter single bud plants or 4 top plants, would be much quicker in veg (just more plants)
so greater harvest yearvise.
more tops delay growth.
plant only can process so much nutes per day and therefore multiple tops at the beginning will slow growth and the more the more tops.
of course later, this can become an advantage, but by then you got a huge plant and hard to deal with indoors.
plus like i said, even outdoors, if the buds dont pull apart from eachother and dont crowd out the light, skimpier harvest.