Well there's still a lot of unknown variables. Such as how did the shattered planet fit into the zodiac? And are there other bodies that we don't know about?
I think that the reason even the genius astrologers don't get 100% accuracy is due to what we don't know about.
There is some evidence that the Sumerians had some kind of recognition (or astrological tradition) regarding the shattered planet (Tiamat)-which might be the source of our asteroid belt. However, it seems that the various types of astrology we find in the world today, are all post-Tiamat systems. developed to address the new status quo AFTER the destruction of that planet (which was between Mars and Jupiter)...