Not really. It's standard practice in nay sort of agriculture to plant many more seeds than the number of mature plants you seek. There are always losses, so you plant lots, take the losses, and then thin as the plants get bigger. If I wanted to get four mature marijuana plants, I would start at least a dozen plants. If you are only allowed to have fur baby plants growing, you are likely to only get a yield of one or two mature plants. 

Further, the four plant restriction is fine for indoor growers, who can get multiple crops per year. If you grow outdoors (which should be encouraged) you only get one crop per year, which needs to produce enough yield for the whole year.