Below is the figure depicting the four types of cooking aromatic categories (where an aromatic is any spice, herb or aromatic vegetable) and their maximum suggested ratio of use. The ratio expresses the dominant aromatic category compared to supporting categories. For example, if savory aromatics are dominant, the ratio of use is generally four parts savory aromatics to a maximum of one part of each of the other categories by weight. Note that this is merely a rule of thumb and not a hard rule, applying to dry ingredients only and not to fresh ingredients which contain a varying degree of water.
The status of spice knowledge in the Western world has been entirely flabbergasting. The fact that no one in the West—in print or in person—has yet provided anyone else with so much as a theoretical framework around which to base a rigorous spice blending technique is shameful. It is, after all, not just important which spices you add to a dish, but also in what proportions. To date, everything where spices are concerned is entirely ad hoc; literally, chefs standing around, tasting their dishes and thinking, “I guess this could use a bit of clove.” I’ve searched and there is literally not much more available than lone chefs guided by vague tradition and his or her own subjective taste.