advocating for Ceres and Juno!
They could be promoted to full rank as rulers of Virgo and Libra respectively.
Already there is more than one system of rulership,
the original one with the Sun, Moon, and only five other astrological planets,
and the most popular one with 10 planets (adding Uranus, Neptune, Pluto) that lets Venus and Mercury rule two signs each - Taurus/Libra and Gemini/Virgo respectively - to cover the 12 signs.
This would be one more system - it's the one I use these days: 12 planets, 12 signs, 12 houses, it works.
I have been influenced in this opinion by astrotheme, and I don't remember which other writings, where I've seen many times descriptions that suggest this direction.
Ceres, the biggest of the four minor asteroids used besides Chiron, is associated with the mythological goddess of growing plants and harvest and also symbolizes physical constitution, vitality and fertility. She's also known as Demeter, according to the astrologer Zipporah Dobyns, linked to the symbolism of the mother but in a less emotive and more physical way than the Moon. Ceres is thought to be the ruler of Virgo, in exaltation in Gemini, in exile in Pisces and in fall in Sagittarius. Keywords associated with Ceres could be order, practical sense, worry, precision, modesty, method, sobriety, motherhood, fertility, the Earth: a kind of a more cerebral Moon...
Juno is the asteroid corresponding to the adaptation to the marital partner and to the defence of individual rights; it is thus used in the field of marriage.