There is a stagnation point at the very front of torpedo shaped objects. An excellent place for an air intake. The EZ-Hook is using a good idea.
The frontal area and drag coefficient method is empirically based. In other words, it is an observed relationship. It is useful and our traditional way of looking at things. It is a simplistic approach to a complex problem. It does not give us much to go by when we want to look at a new idea. By necessity, the aerodynamic relationships were examined further and methods were developed that give us the means to arrive at fairly good shapes based on theoretical relationships. Testing is still very important, however.
The concepts Blue is describing are part of the more modern approach. His posts should be read carefully and considered. They have valuable information.