Recommended authentication method

On the Sigma Docs (https://help.sigmacomputing.com/hc/en-us/articles/360036944534-Manage-Authentication) there are 5 methods mentioned:

Password
SAML
SAML + Password
OAUTH
OAUTH + Password

What is the recommendation between having a single method like SAML or OAUTH and either one of those with Password in addition?
When would one use a combination like SAML + Password?