Strength in Image

I am currently writing a short paper on the issue of political artwork. This is a piece that my art history class has been studying by Jacques-Louis David called the Oath of the Horatii. This is considered political in content and style. The man in the middle is the father holding three swords up to his three sons as they take an oath to fight for family honor as well as for their country. This painting I consider to be strong not only in content but of placement of the images on the picture plane. If you notice, three is a reoccurring statement. There are three swords, three brothers, three arches, three distinct triangle and so on. Three is a strong element, for example if you have a bicycle (which is two wheels) it can easily be pushed over, but if you have a tricycle (as you know has three wheels) it cannot be done as easily. The triangle, in it's self, is a strong image because there is a good foundation to it. So in the painting it could be referring to the foundation of their family.
This summer, I saw this piece in Paris at the Louvre and I didn't know what it was about. I am anxious to get back and see it again.