I'll give some examples.My sister and her husband had the pr composite Moon conjunct their composite Sun on their wedding day.
My mother and father had their pr composite Moon in the opposite sign of their composite Moon.
Their pr composite Moon and transiting Moon were conjunct that day.
I've checked several other charts and saw the Sun/Moon theme repeated each time.
Another example was with my friend. She and her husband have Sun and Moon inconjunct in their composite. On their wedding they had the same aspect to the degree in their progressed composite.
Maybe you guys could check the composites of married people you know to see if you notice this pattern, too.