The term "Heaven, Earth, Man" is used in may different situations.
We can say that it simply means "When, Where, What (action)". To get the best result, we have to do the right thing at the right timing and the right place. This is the microscopic assessment of an event. A good feasibility study can be very scientifically structured.
In metaphysics, we try to study the lives of people using their birth data. We conjecture that the qi structure at the moment of birth describes the potential of a person in many different aspects. In the four pillars studies, we are not just talking about the five elements and whether the chart is balanced or not. We are studying the interaction of the qi in various parts of the chart. This changes with time as the current external qi interferes with the internal interactions. For example, the ability to make money may be weak in the natal chart but time can make it strong. Time can also bring friends and partners to help the person make money. Time, in addition, may also bring romance opportunities to the person. Thus two people with the same four pillars chart may have different outcomes. One may make good use of the timing to get rich. The other may make good use of the luck to enjoy romantic affairs. The outcome is that one gets rich while the other does not. This is by choice and not by birth.
Each element has several representations in a four pillars chart. The same element can do different things in a chart. It is up to the person to take whichever representation and to do whatever according to his free will. The outcome will be totally different.
It is naive to say that astrology is nonsence because two persons born with the same chart have totally different lives. It is stupid to claim that astrology can tell you when you will get married, when you will get rich and famous, when you will die.
Life is like a computer game. Two people playing the same game choosing the same weapons will have totally different results. That is why.