Correct.
Kickstart 3.0 only exists for A1200 and A4000 (desktop).
For a while, workbench3.0 (AGA) and workbench2.1 (OCS/ECS) coexisted in the market (until 3.1 was released).
Kickstart 3.1 was later made for all amigas.
All A4000T's (genuine T's made by C= or Escom) were shipped with 3.1, as were all CD32's (the first amiga with kick3.1).