Maybe the planets were metaphors for other things, after some additional elements from the Europeans, those planets took on the meanings we have now.
By 450 BCE the Babylonians had developed the 12-sign zodiac, but it was the Greeks--from the time of Alexander the Great to their conquest by the Romans--who provided most of the fundamental elements of modern Western astrology.
Why are the initial conditions more important than all subsequent conditions for oneís personality and traits? Why is the moment of birth chosen as the significant moment rather than the moment of conception? Why arenít other initial conditions such as oneís motherís health, the delivery place conditions, forceps, bright lights, dim room, back seat of a car, etc., more important than whether Mars is ascending, descending, culminating, or fulminating? Why isnít the planet Earthóthe closest large object to us in our solar system--considered a major influence on who we are and what we become? Other than the Sun and the Moon and an occasional passing comet or asteroid, most planetary objects are so distant from us that any influences they might have on anything on our planet are likely to be wiped out by the influences of other things here on Earth.