Updated: May 31, 2020
By not spending a little time to research on how to properly sow seeds, this is how I planted different types of seeds in my new container boxes to maximize my harvest. I thought you plant seeds the same way for all vegetables and the closer you packed them, the better. (What a disaster!)
After reaching out for help, this is the feedback I received, which taught me the missing step in this video. Thinning.
Welp... I commented without seeing the video. No, you shouldn't over-sow to squeeze more plants into the same-size plot. You should over-sow to be able to thin to the strongest and maybe have a few backups, just in case.
You should always sow as many seeds as you can manage, as long as you can get yourself to thin them to what you have room for. The more you have to choose from, the higher the chance that what you've (judiciously) thinned to are indeed the strongest; the stronger the transplants, the lower the chance that a screw-up on your part will lead to a dead plant.