I will carefully construct a PPC structure for each of your Parent ASINs, the approach behind the structure is the result of spending over 9 years of trial an error with a background in marketing honing it to perfection.
Managing it is a lot like gardening, where I start with "seedling" campaigns which provide me with data to add additional layers to the structure, prioritizing the experiments that are more likely to succeed. Every layer provide more data, but it can also come with more risk, so the idea behind the approach is to get stability on each layer (cost-efficiency) before adding another one.