Why Bach's fugue subjects never begin on the submediant ? (Fugue in A Minor - original composition)

Do fugue subjects often begin on the 6th degree ? I haven't seen any ! Tell me in the comments ! Anyway I do hope you will enjoy this original piano composition what is a fugue in classical music study music for concentration counterpoint theory ____________________________________________________________________________________________ The Preludes & Fugues :    • Preludes & Fugues   The Sinfonias :    • The Sinfonias   The Inventions (revised 2021) :    • 15 Inventions by studentofcounterpoint   The Inventions :    • The Inventions   The Waltzes :    • Waltzes   The Little Preludes :    • 6 Little Preludes