I don't see the search for protophenomenal constituents to mind as being that outlandish. Afterall, even with the physicalist reductionism of matter we assume a certain continuity of properties starting from the whole all the way down to its atomic parts. "Protophysical" properties like mass and charge for example. It seems sort of basic to me to assume the same will be the case for mind if indeed we are bent on some sort of reductionism to irreducible units. Leibniz attempted such a atomistic ontology of "tiny minds" or monads as did Whitehead with his actual entities. After that higher level mental properties can be logically inferred as merely quantitative sums of lower level protomental properties. But I suspect that alot of the explanation for mind, if indeed such is even possible, will involve a mapping out of the hierarchal structures (as well as novel properties) that emerge from bottom to top. IOW, it won't do to just have an aggregate of protothinking units in order to explain mind. We will have to take into consideration all the functions and processes of said units in their structured relations and interactions with each other.