The four Royal stars are supposed to have their origin in ancient Persian Astronomy. As most things in religion and astrology, the sources for this are dubious from a historical perspective.
The Arch
angels were probably attached as an
aspect, at a later time.
https://en.wikipedia.org/wiki/Royal_stars
https://mysticmedusa.com/2016/04/fixed-stars-astrology-the-watchers/
Fun fact: Archangel was a rank above Elite in some versions of the original game.
You've hit on another point of contention there. The spelling of "angel" and "angle" since when dealing with astrological "aspects", opposition (180 degrees) and square (90) in the case of the four fixed points of the zodiac, you're in essence looking at the relationships between the archetypal bodies.
The challenging aspects above, and also including 45 degrees could be looked upon as demons since any activity you attempt under these alignments of the 'gods' (planets) are likely to at least be difficult if not cursed to fail outright and are therefore best rescheduled until a more favourable hour.
The 120 degree 'trine' signifies 'easy luck' while 60 and 30 degrees are known as 'sextile' and 'semi-sextile' respectively and signify pretty much what they sound like you'd expect. In short, the aspects, angles or angels between the planets are smiling, so you better put on your best business booties.
Think of it like surfing the cosmic current (hours / Horus / Horus-scope). You wouldn't catch a dumper or try to swim against the tide. The gods are doing their own thing and really don't care about you, at all but if you can attach your little wagon to an activity they're already doing you can use their influence.
Ignore it if you like, they won't care. Or, use the angles / angels to amplify your efforts.
[Note: Arch / arc appears in this context a lot too, as in divisions of arc across the sky.]
[Edit: When casting spells one must be aware of phonetics, incantation, logos sounds]
www.edsm.net
