“Like dissolves like” is an old rule of thumb that works well and applies to herbal extractions.
There are two major groupings of medicinal plants: plants that mostly produce Terpenoids, and plants that predominantly produce alkaloids.
In centuries past, terpenoidal plants were extracted with wine (because of the alcohol) and alkaloidal plants were extracted with vinegar (because of the acid content).
We have all noticed how terpenoids (including cannabinoids) are hydrophobic (dislike water), but are easily extracted into alcohol, essential oils and lipid oils. Alkaloids, on the other hand, do not dissolve easily into oils, but are mostly freely soluble in water, and even more soluble in weak acid-water solutions like vinegar and citric acid.
As a general rule, if an herb isn’t very soluble in either water or oil, then, a third option is to try a sugar solution, such as honey, fruit sugar, or vegetable glycerin.
Picking the correct solvent is always a the critical step in extractions, and the rule ‘Like dissolves Like’ is a reliable rule towards that end, and has been for several thousand years!