If you find yourself using complicated custom methods with Dockerfiles, you should probably be building Linux packages, publishing to a local repo, and installing them from the Dockerfile. You gain the idempotent, immutable, versioned, system integrated, dependency-mapped, cryptographically verifiable, remotely distributed, cacheable benefits, and you don't have to adopt any new software or systems.

Your organization can follow any workflow/lifecycle it wants to build and publish the packages. Once they are published, developers can just install and use them with no learning curve whatsoever.