I see, someone is eagerly practicing best practices from “how to successfully fail a project” ^^
What I recommended in my first post is what I would do: single application in a single container implementing a strategy pattern.
Generaly, I would highly recommend to take this self paced training to get a better understanding of docker. It provides better information than any 3 day docker onsite training I have participated in (I had two).
Good luck on your journey!