I think the confusion here is the type of mixes being discussed. As the first and following posts of this thread indicate, the topic in question is mixing components together in a bottle and juggling the concentrations and amounts needed to produce a mix with a specific yield of each component per spray.
I believe what you’re commenting about is more towards applying individual components separately by either spray, dab, or drop from a bottle. If I were to try to apply a drop of 5000 mcg/ml component, there would be very little accuracy or precision possible since the method only allows for specific unit quantities of distribution (1 drop, 1 dab, 1 spray). In that respect, you would be correct with your assertion. However, in the context of mixing in a bottle, that no longer applies since we are combining multiple components together in a process that by definition dilutes the concentration of the component and is affected by the quantities (volumes) of other components.
For example, if I were to mix 2 ml of the 5000 mcg/ml component with 8 ml of alcohol, that would produce a mix of 10 ml with a component concentration of 1000 mcg/ml since it only composes 20% of the mix. Now if I were to mix 2 ml of the 5000 mcg/ml component with 98 ml of alcohol, a 100 ml mix with a component concentration of 100 mcg/ml would be produced (2% of mix).
If I wanted my mixes to have a high concentration of my desired component, I would have to start out with a higher concentration since mixing (especially with large volumes of other components) will dilute my component concentration. For example if I have a bottle of 25 mcg/spray P74, if I used just the spray, my usable maximum concentration/spray is 25 mcg/spray (100% of mix). All my mixes will never exceed 25 mcg/spray of P74, and if I mix other components into the mix, the concentration will be significantly lower. To maintain a desired concentration at the 25 mcg/spray level, I will have to use a higher concentration strength of P74 (50, 100, 150 mcg/spray, etc) so that after mixing and diluting with other components, I can still end up with a net mix concentration of P74 at 25 mcg/spray.
It would probably be easier to distinguish between the 2 methods of mixing. Most of the “mixes” that I see are usually a combination of sprays or drops (e.g. 3 sprays of Ammo, 4 sprays of Instant Shine, 2 drops of A314, etc.), and I think it would be easier to call these “Combinations” or “Combos”. On the other side are true mixes that are composite blendings of different components together into a new mix that is used as a stand-alone product. These should probably be referred to as “Mixes” or “Potions” as I like to call them sometimes 