I don't use the astrological associations attached to the tarot to speak in astrological terms, I use the astrological associations similar to the concept of using Arabic symbols for English numbering. That is, I'm not using, say, astrological "Mars in Aries" to describe to me the two of wands, but "The Tower in the Emperor" (hard to explain).
As for answering your concern about the 10 degrees and Decans or Decantes, I'm sure Jim will provide solid arguments for his ideas. The basic thing is this, dividing the sky into 36 segments of 10 degrees was something that came into fashion about the time the Golden Dawn was active. This may or may not be a valid thing for astrology (i'm not an astrologist, but Jim is, and his arguments should be observed). But the notion that the minor arcana have a 36 number to them, the same way the tarot as a whole has a 3, a 7, a 10, and a 12 in it, means they can be associated.
Don't get overly worked up about it. If it doesn't work for you, then don't heed it. But don't give up without exhausting yourself.
"If we are to have Beauty and Love, whether in begetting children or works of art, or what not, we must have perfect freedom to act, without fear or shame or any falsity."