I myself have very little knowledge of astrology, and base myself on Qabalah. When considering the astrological attributions, I mostly read their stories, and it does work. The attributions on the cards serve less to give astrological information, but more semantic connections, and they do this very well. For example, Sun in Ares could refer to someone born in February/April, but it works better if you consider the Sun energizing (as it does with all signs, astrologically) the Ram, phallic, single minded, strong, willful yet in balance, because it isn't at war with anyone. This gives us Virtue, the Three of Wands, appreciation of one's inherent power, etc.
Once you get into the spirit of looking at things from that perspective, you begin to pick up connections between cards where they were not apparent before. For example, Taurus attributed to the Hierophant is ruled by Venus, but the Moon is exalted in it. Cancer attributed to the Chariot is ruled by the Moon, and the Priestess is attributed to the Moon. So there is a connection between the ideas these cards put forward. What those connections are is probably up to you to decypher. It may seem confusing, especially the way I'm explaining it, but it gets easier. You can find connections between the Majors and the Minors (the Three of Wands could be thought of as the Sun card shining on the Emperor card)... the possibilities are endless, really. Just jump in, it'll all be clearer in time.
I think you've just handed over the key to this tarot business... 