This will explode currently; but for discussion

Right, so I realised we also use the same things directly or indirectly for network attach, so methods using those would / should also be updated accordingly if we want to do this.

And ... probably it makes sense to have them the same, because effectively the container create is a "create a container AND attach to <list of networks>" on the daemon side

35.61 # github.com/moby/moby/v2/daemon
35.61 daemon/create.go:390:45: cannot use v (variable of type *"github.com/moby/moby/api/types/container".EndpointSettings) as *"github.com/moby/moby/api/types/network".EndpointSettings value in argument to validateEndpointSettings
44.94 # github.com/moby/moby/v2/daemon/server/router/container
44.94 daemon/server/router/container/container_routes.go:693:32: cannot use networkingConfig (variable of struct type "github.com/moby/moby/api/types/container".NetworkingAttachOptions) as *"github.com/moby/moby/api/types/container".NetworkingAttachOptions value in struct literal

To some extent even considering if NetworkConnect should actually be considered part of the Container API; it's currently reversed (take a network and attach a container);

But perhaps the reverse would be to enhance docker container update, to add options for adding / removing networks, similar to docker service update;

docker service update --help | grep network
      --network-add network                Add a network
      --network-rm list                    Remove a network