Subscribers’ exclusive: Why do commercial products use several different emulsifiers and thickeners?

In the July Q&A, After doing ingredient studies on some of my favorite high end organic products (Tata Harper, Eminence, Tracie Martin), I’m finding that, more often than not, several different emulsifiers, thickeners and preservatives are used in the same formulation. This mystifies me! Why don’t they pick one? I understand using several different humectants, emollients,…