This feels like a hacky solution.

Why not use VLANs? You can have just one physical interface and then have VLAN interfaces. You can then use a bridge to have every container have their own interface and IP that is attached to a specific VLAN.

So containers have been standardized for a while now (OCI), and even if you install “docker” it’s actually just installing containerd with docker-cli. For years kubernetes is not even supporting docker-shim anymore. So there should be no issue. What is even the problem you are running into?