Triplicity rulers vs. Term rulers

1
Hello,

In going through Dorotheus of Sidon, "Carmen Astrologicum", translated by David Pingree, I found that the Author (Dorotheus or whoever it was) put a lot of emphasis in Triplicity (Trigon) rulers of the zodiacal signs. In fact this was his first lesson (in Chapter 1), making sure that his son (or whoever it was) understood the different triplicity rulers. The Arabs (many of whom relied heavily on Dorotheus) also used a lot of these trip rulers in their astrological texts. Bonatti (who compiled many of the Arabic sources) also outlined the three trip rulers for each house governing different areas in the said houses and a detail account of directing by triplicities - the idea that every one third part of life is governed by the three trip rulers of ascendant (if you follow Bonatti) or main luminary (if you follow the Arabs).

Meanwhile, other authors (the Author of Liber Hermetis) and Firmicus Maternus (author of Mathesis) relied heavily on terms and term rulers. Examples are abound in Liber Hermetis of the effects of planets in their own signs or terms (not exaltation, not triplicities!). Firmicus used a lot of term rulers e.g. in delineating wealth, one of the requirements is that the sign ruler and term ruler of Part of Fortune should aspect the Part itself (not exalted ruler, not trip rulers!). Even Bonatti gives priority on term ruler (of Hyleg) for the determination of Alchocoden (not exalted ruler, not trip rulers).

My first question:-

1. Why are the triplicity and term rulers given priorities over exalted rulers but at the same time the exalted rulers are always given higher dignitiy points (4 for exalted rulers, 3 for trip rulers and 2 for term rulers)?

My second question:-

It seems to me that there are 2 camps of astrologers. Those who give emphasis to sign and trip rulers and those who favor sign and term rulers.

Why?

If there are actually no 2 camps of astrologers (just different ways of looking at things), how do these astrologers decide that for this matter we look into term rulers and for that we look intro triplicity rulers?

Thank you in advance...