I don't understand your question DK. A synastric Sun square Sun aspect would become a single Sun in composite. Say I dated a woman who had Sun in 10 degrees Pisces and I am Sun 10 degrees Gemini. Then our composite sun would be the mid point, i.e.25 degrees Aries. A composite is a single entity, one chart: only one placement in it of each planet and point. As CC and I said, the composite chart shows the shape and dynamics of the relationship.

chris