delta would be less ootb policies (though lots of github repos with examples re awesome custodian lists), and more user defined policy as code (dsl and gitops style) with integration into serverless provider platforms for continuous monitoring, along with remediation support and platform integrations (security hub, google cloud security command center, etc).

other tools in this space on the detect and report side (albeit aws specific) https://github.com/toniblyx/prowler https://github.com/jonrau1/ElectricEye

on the gcp side forseti, https://github.com/forseti-security/forseti-security