Astrology and spirituality are like two sides of the same coin. I would say one is the horizontal to the vertical line forming a cross.
Astrological and Spiritual symbolism are both man-made interpretations of metaphysical philosophies of life.
For me, they represent the same side of the same coin. The symbolic equations are just focused and explained differently to reach the same answer.
Spirituality motivates you to move forward, to live, to spin the wheel - fire energy;
while Astrology has you stop and ponder on the elements and variables that configure this movement - earth energy. Ying and yang. Life and death.
The fire of Spirit = Sun. Its 'spirit'(uality) is shown through its sign at birth; the element (temperament) through which it will be expressed.
Its path is not always straight forward, as per traits and functions of other signs and planets it meets along the way ... within other people and within Self.
Aries axis Libra representing Spirit and Energy (life), Taurus axis Scorpio representing Astrology and Mystery (knowledge).
From which form and technique of astrology is that taught?
There is a problem with accepting a set of characteristics as your personality and being - seems like it ties you down and takes the life out of things. "As if things are written in stone" .
Which is a traditional astrology/Old Testament perception of life?
I.E. Like Saturn influences, neither appear to allow the inclusion of choice and free will in leading it.
"I'm not anything like my sun sign! Astrology is nonsense!"
Perhaps because many people are Moon reactive feeling orientated towards life and have need of other parts of their character to deal with its effects, eventually showing their 'spirit' of what they are made of.
However, there is another truth that is to be reckoned:
As we know there's always movement - as the wheel spins.
Most astrologers know about progressed charts. But do we all account that when describing a sign? How Fire signs progress into Earth signs. Earth into Air. Air into Water. Water rebirth into Fire. The movement that is.
My all-time favourite lyrics, 'The Circle of Life'.
I go along with your line of thought which, basically, depends upon the astro. learning and/or schooling an individual has undergone and developed.
Many (experienced) astrologers do not consider and use progressed techniques WITH transits. The 'turning of the wheel' sees so many life-changing experiences that enables the natal Sun sign to become even stronger in Spirit = the 'spirituality' so many seek.
Doesn't it boil down (or up) to be(com)ing the essence of one's Self?
My ½ cent of simple Earth-Air influenced philosophy.