Take the following semantic groups in English:
- Politics; political; politician.
- Mathematics; mathematical; mathematician.
- Music; musical; musician.
The pattern is clear: given the noun for a discipline, you can add the suffix -al to form the adjective meaning "related to such discipline", or you can add the suffix -ian to form the noun meaning "someone whose profession is such discipline". Thus getting distinct words for each concept.
In Spanish, however, it seems to be more common to use the same word for several, if not all of those different meanings:
* Though the DLE still defines músico, a as «1. adj. Perteneciente o relativo a la música. Instrumento músico. Composición música.»
Question: has it always been like this? Did Spanish ever had a specific suffix for the above professions, equivalent to English -ian, and then it got lost? Why (or why not)?