Actually, you'll find that it's not "an" ancient systems, but several different systems. Lots of it is based on interpretations and experiences with different energies. The calculation of the energies is standard. It's what you do with it that matters. What Marie calls a power star, another master might just call a "good location". We agree (largely) on the types of energies present. The effect is the same whatever you call it. The ways of working with energies differ from master to master. For example, days I favour building the energy flow into the structure of the house rather than "curing" or "activating" energies, but that's just what works for me.
Mayflowers:
I don't get hung up about the "power star" activation because I haven't really looked at the energies with that label for a long time now. I simply move the energies I want into the sectors I want. Marie's approach is a valid interpretation and approach to using the energy present.