Using multiple authenticatin policies with Okta

[Dominik]

I crated a secondary authentication policy for Okta SAML for our domain. I also see there is a default policy for all members. Can we enforce Two-step Verification for this default policy without it affecting our secondary authentication policy used for Okta?

Or, is it better to setup a third authentication policy for external users (those not on the domain used for Okta)?

Thanks!