Different kinds of triads

A variety of triads in Etruscan and Roman mythology are available to the imagination of the mythologist. Among Romanists, one speaks of a Capitoline triad (Jupiter, Juno and Minerva), an Archaic Triad (Jupiter, Mars and Quirinus) and an Avertine Triad (Ceres, Liber and Libera). Even the festival of Suovetaurilia is split in three - a sacrifice is made of a pig, a ram and a bull to Mars in order to sanctify the land. Amongst Etruscans, we can identify the Trinity of Tinia (Tinia Cilensal, Tinia Thufal, Tinia Thneth), the Trinity of Maris (Maris Husiurnana, Maris Halna, Maris Isminthians) and the Chimeric Triad (snake, lion, goat). The list seems to go on indefinitely. Our modern understanding is no doubt blurred by the mists of time and hampered by organizational laziness. There must have been a greater structure and meaning in all of this. Something clearer, more verstaile and not so complex. But what?

In my search, I find it handy to reclassify these triads into flexible categories, recognizing that these religions were so prone to creative symbolism and lateral-thinking analogy. So I'd like to suggest some helpful groupings as follows:

Solar triad:
The sun is divided into three parts: three seasons (winter, spring-summer, autumn) and three daytime periods (morning, noon, evening). Think "Father Time". This stems from the heliocentricity of Etruscan religion.

Etruscan: Tinia Cilensal, Tinia Thufal, Tinia Thneth (Trinity of Tinia); Snake, lion, goat (Chimeric Triad).

Roman: Jupiter Summanus, Jupiter Fidius, Jupiter Tonans.

Seasonal triad:
The year is divided into three seasons (winter, spring-summer, autumn) with focus on agriculture and cyclical climate changes. Think "Mother Nature".

Etruscan: Maris Husiurnana, Maris Halna, Maris Isminthians (Trinity of Maris).

Roman: Jupiter, Mars and Quirinus (Archaic Triad); Ceres, Liber and Libera (Avertine Triad).

Astral triad:
The three brightest bodies in the sky happen to be the sun, moon and Venus (in that order). Thus: Tinia the sun, Menarva the moon and Uni the planet Venus. This is a twist on the pre-existing Babylonian triad.

Etruscan: Tinia, Uni, and Menarva (Capitoline Triad).

Roman: Jupiter, Juno and Minerva (Capitoline Triad).