More plants will save you the time of vegging and cropping multiple times. Three plants with two weeks of veg is as good as one plant with six weeks of veg. It's going to save you a month, and a whole lot on electric, that's for sure.

I agree that it can be a time saver but why do you want three pissed off plants that will be fighting for root space and nutes instead of one happy healthy plant. More plants is usually a way to go just not in the same container unless its a large bed or something like that. Especially when running DWC, you create a lot of roots that generally fill the bucket with one plant. Also look at the risk vs reward factor. If you are currently running an average of 60 flowering plants why take the risk of crossing the federal mandatory minimum threshold by growing 120 or 180 for the same yield? Another thing to think about is if one of the three gets root rot or any disease you WILL lose all three. I have done a side by side experiment on this and several variations. The single plants ALWAYS perform just as good or better than any number of multiples sharing a root zone. The multiple plants may have as much canopy and LOOK as good but without good roots you get no good fruits. You will get a larger ratio of unusable popcorn nugs instead of decent colas coming from a mature well rooted plant. If you dont mind smaller nugs or high plant numbers just do a reguler sea of green and keep them all in individual containers. I am sure if you ran 2-3 per bucket in a commercial setup they will not all grow evenly, your canopy height will be a mess. You will always have a weakling in the group that is shadowed by the others and performs shitty. You will be wasting nutrients, light, and plant numbers on at least one per bucket.

Both StonerB and another_sellout have good points and should be taken into consideration. All I can say is try it! No one grows like you do and/or in the same environment. So to know if it will works for you try it. You will flower when they are short (10" on the average) just like SOG plants.
I personal use the SOG method for years. I use trays but essentially they are in one big pot; roots grow together; plants fight each other for light ect. But I've seen the with just one plant (fighting itself for light indoors). If you try it and it works/you like it. Quick turn around; harvest; easier; or for what ever reason. I would then change your system to ebb/flow trays. It will maximize the space and you'll be able to add more plants, for a bigger harvest.

Good luck