Medicine men are typically accused of being in league with satan so they were killed. They had different explanations for why things happened and what to do about it. This means they are not part of the group (when the group believes in something different).
Believe it or not, lobster and crabs are crustaceans and are a part of the arthropod family, which include caterpillars, cockroaches, and spiders!
A Galactic Funking Hunt Wit Not Wont