....This is just a misunderstanding by people who couldn't figure out the doctrine brought to us by an Eastern Greek....
Eastern Greeks were a conduit for information from Mesopotamia via the Sumerians. The Eastern Greeks passed on knowledge in math, science, astronomy and astrology first from the Amorites (mistakenly referred to as "Babylonians") and later from the Babylonians (mistakenly referred to as "Chaldeans") to the nucleus of what would later become "Western Civilization".....
This Eastern Greek -- Nechepso was his name -- espoused a doctrine of 8 power regions in the Chart, and you know them as Angular and Succeedent Houses/Signs.
That, is the source of the 8-Sign Zodiac Nonsense, in spite of the fact that Nechepso never said there were 8-Signs, rather he said there were 8 regions of power in the Chart......
This doctrine caused some confusion, leading some of the later astrologers, mostly Hellenistic --- like Dorotheus, but even Zael used it, to adopt the 7-Sign/House System of power, which was the 1st, 4th, 5th, 7th, 9th, 10th and 12th Houses/Signs.
Surely you can see the confusion --- the MC can fall in the 9th, 10th or 11th House/Sign, and so how can you have a king with a 9th House MC or MC Ruler in the 9th?
And what about the 2nd House of Wealth?
That leads to weird things like the 15° Rule )Ptolemy) where a Planet within 15° of the Ascendant (or MC) is considered to be in the Asc/MC.
That's what happens when subtle (and not so subtle) nuances get lost with the transmission of knowledge over time. I don't think Nechepso & Co or Ptolemy & Co are necessarily wrong....in fact, I'm not even sure they were talking about the same thing, and there's every indication that the Asc/MC were treated separate and apart from the House/Signs.
Even so, they all still pretty much say the same thing, that there's a distinction between looking at the Chart as a whole, and looking at Topics.
Suppose the Chart Ruler is in the 7th House....that's Angular, and (assuming it is otherwise in good condition) you could conclude that nearly all of what the Chart promises will be fulfilled --- it's just a matter of determining when (use Profections and Revolutions).
Now suppose the Chart Ruler is also the Wealth Ruler.....would you draw the same conclusion?
No....it's Angular in the Chart, but not to the Topic of Wealth....the 7th House would be Cadent to the 2nd House/Sign, and in fact the Topic Ruler can't even "see" the House/Sign it rules, and so it is powerless to do anything, regardless of its condition.
You can also view it as Public (Angular), semi-Private/semi-Public (Succeedent) and Private (Cadent).
Are all powerful men and women in the spotlight? On stage? In the news?
No....well, then you might want to look and see where the Topic Ruler (in the this instance the MC Ruler) is located. Same for those who have wealth...of any kind...how many times have you seen the modest person....only to discover much later that they have a rather fair amount of wealth (to a lot of wealth)?
You can also view look at those power regions in terms of "longevity." Some people retain their wealth and/or health their whole lives, while others see their health/wealth fade with age....or lose their friends....don't age gracefully....have fewer enemies....fewer employees...their power fades....their zeal for things religious, ideological, educational or philosophical wanes.