Tropical zodiac: it's the zodiac that has a logic built into it that is both naturally derived but then also illustrative of all the qualities we attempt to understand through astrology. The whole idea of "bursting forth in a fiery and life-initiating way" is exactly an interpretation of what the increase of sunlight on the face of the earth encourages each year when it passes the vernal equinox. It's the perfect combination of temporal, ambient, organic, and metaphoric resonance that is applied/yielded through mathematical understanding. It's something we can see and touch and measure and observe and predict and understand, and then use as a metaphor everywhere else in the universe we see the interaction of energy and matter, heat and moisture, light and dark, angularity and geometry, creating and defining reality. It's a true example of micro/macro relationships too, because all the swirling maths involved hint at the nature of atomic realities as well as galactic ones: sphericity , angularity, and energetic interaction between dense points of matter.

Associating natural qualities to star groups a la sidereal zodiacs is not tangibly relative or relevant to anything discernible in our experience. It is only anchored in a religious belief, ultimately. Designating stars as constellations is helpful on a generational-scale in order to make navigating and timekeeping universal and easy, but giving qualities to the random clusters of stars out of which we pick the shapes is transferring the natural qualities the interaction of heat and moisture reveals continually as the seasons play out. What's the actual reason for saying distant stars convey qualities to our solar system if it's not based on ancient religious concepts? Sidereal zodiacs only seem to have appeared around the time the current constellation of Aries was in fact synced with the sign of Aries. I think people just got stuck and refused to shift with the axial precession thereafter. Who knows tho. There's still no logic or discernible magic behind the idea while tropical explains all nature, all magic, and all geometric metaphor exactly.

Whole sign: because eventually you figure out that the concept of a house had always been intended to describe the entire signs in the order they were going to rise at a given time and location. Simple. We say things like how any planet founds in a sign should be expressing the qualities of that sign somehow, but then when we start elevating a sign at the horizon we suddenly forget that. The whole sign system is the only one that actually allows for a rising sign to be rising. Action word. The ascending sign should be ascending. The rising and setting signs are conveying what is above to below and vice versa in the moment as an action, and the sign that is carrying that action is expressing itself as something that is coming into or receding from being. It gives an incredible nuance I guess you don't see until you use the system where part of the rising sign can still be building just below view while the other part can now be officially extending up into the interpersonal sphere. Something can be in the first house but just below the horizon or can have already risen and still be separating itself from the ascendant but rooted in what is still below the horizon. Once things separate officially from the ascendant they find they are the 12th house, and it makes perfect sense that once our actions and expressions are released and given into the ambiance they are beyond our control ... and we must suffer the results. Ever wanted to take something back as soon as you said it? 12th house. House of "imprisonment" and the first house of the interpersonal sphere by diurnal motion. Ever caught yourself at the last moment juuust before saying the thing you'd wish to take back? Still separating from the ascendant. Right? If a whole sign embodies a general attitude (as having been defined by the sun creating that season) then designating one as the first to be rising, then the second to be rising, then the third gives us an idea of what kind of overall motivations from within or from the past are supporting what is happening, how, and why.

Also, the Gauquelin sectors basically illustrate or prove that the real potential of activity is just above the horizon ... and since we understand the 1st house to be the active one as opposed to the 12th house which is the first inactive one ... we see how the first house likes to be rising into view but still connected to the singular motivation that is usually still partially out of view still. Just like real life circumstances tend to reflect.