Let's take the analysis a step further. The fixed mode is lacking in the prime triad. Another way to approach the synthesis of the sun, moon and ascendant is to turn our consideration to that of elemental compatibility. The prime triad is made up of two earth signs and one water sign. Water and earth are generally considered to be compatible elements.
Water nurtures the earth and earth absorbs water.
However, one challenge of this combination can be that more water is needed to nurture the earth. Further, the foundation represented by the prime triad lacks the air and fire element. Let's consider another example. Water puts out fire and air evaporates water. But don't stop there.