Well, sorry to throw my 2 cent's into the ring, but I've felt that one's natal Aspectarian - the compilation of all the angles the planets, asteroids, fixed stars, Arabian parts and House cusps all make to each other, was the "Meat" of 'Astrological Significance' as well as the best indications of strains and augmentations in the materially manifest 'corpus' of the Overleaves. Personally, I can look at my Natal Chart, and see just how my Essence used the Gravity Waveforms, relative vectors of magnetic flux, fieldstrengths and the progression of all these bodies that bend spacetime and combine and repel to create rough waters or fair winds as one sails one's life through the unfolding futures we choose.
THE MOST IMPORTANT ASTROLOGICAL AXIOM TO REMEMBER IS: "THE STARS DO NOT 'COMPELL', THEY SIMPLY 'INCLINE'"
Astrology is MOST influential IN THE ABSENCE OF OTHER FACTORS during which it seems to me to be most significantly acted upon by Ebertin's "Asteroids At Midpoints" cosmobiological descriptions. Usually short, definitive predictions of a nudge or a period of resistence to the native' aims or ongoing life direction, they seem to have an uncanny ability, through transits to midpoints, and activated midpoint trees, to highlight crises pertinent to one's ongoing struggle with Chief Features.
Also, John Roth, are you proficient in "Gauqelin" Chart Calculations? I'm a tad rusty, but, just as things like "highlights and indications of planets on the angles"; asteroids, Arabian Parts and planets near the midheaven were, to Gauqelin's chagrin (as a statistician setting out to 'debunk' Astrology) statistically indicative OF JUST WHAT CONSENSUS ASTROLOGY PREDICTED THEY SHOULD BE. I'll bet you a dollar to a donut that correlating Gauqelin sectors with the MT will prove useful in defining a causal link or two, if anyonehas the time.
Also, the 5 Book Series by Schulman: "Karmic Astrology", utilizing the Moons nodes and the nodal axis, house and sign placement of Pars Fortuna, house and sign incidences of retrograde planets in cadent houses, secondary progressions AND the whole field of VEDIC Astrology, respected for 4,000 years in India are not indicators to be dismissed. The Schulman Books, when applied to one's possible major/minor agreements, the best times (and even adverse/advantageous geographical locations using Astro*carto*graphy)
to attempt to 'burn karmic ribbons', etc etc., all these things have helped me chart the reefs and shoals, and fair harbors, that are CREATED by the confluence of spacetime continuum tides, currents beaches, winds et al.
So while there is no Absolute one-to-one correspondence between Overleaves and Astrology, if your Overleaves are the make, model and options package of your "incarnation vehicle", you'd be stupid to drive across an unknown country without a road map (Astrology) RIGHT?