Well, individual letters in these languages in use* do not convey specific meaning, while individual tokens do - so, you cannot really construe a ladder that would go from letter to token, then from token to sentence.
This said, to research whether the search for concepts (in the solutions space) works better than the search for tokens seems absolutely dutiful, in absence of a solid theory that showed otherwise.
(*Sounds convey their own meaning e.g. in proto-Indo-European according to some interpretations, but that becomes too remote in the current descendants - you cannot reconstruct the implicit sound-token in words directly in English, just from the spelling.)
This said, to research whether the search for concepts (in the solutions space) works better than the search for tokens seems absolutely dutiful, in absence of a solid theory that showed otherwise.
(*Sounds convey their own meaning e.g. in proto-Indo-European according to some interpretations, but that becomes too remote in the current descendants - you cannot reconstruct the implicit sound-token in words directly in English, just from the spelling.)