Are you advocating running multiple sshd instances in this case?

Good heavens, no! You'd only have two different instances of the same service that is difficult to work correctly with.

For serving as a debugging channel and user-facing shell access, SSH is fine (though I've never seen it managed properly in the presence of nodes being installed and reinstalled all the time). But for everything else (unattended):

* you don't want commands execution, port forwarding, or VPN in your file server

* you don't want remote shell in your daemon that runs parametrized procedures -- but you do want it not to break on quoting the arguments and call results (try passing shell wildcards through SSH)

* you don't want port forwarding and remote shell in config distribution channel; in fact, you want config distribution channel itself to be reconfigured as little as possible, so it should be a totally separate thing that has no other purpose whatsoever

* you don't want to maintain a human-user-like account ($HOME, shell, etc.) for any of the above, since they likely will never see a proper account on the server side; you want each of the services to have a dedicated UID in /etc/passwd, own configuration in /etc/$service, own data directory, and that's it

Each of the tasks above has a daemon that is much better at them than SSH. The only redeeming quality of SSH is that it's there already, but it becomes irrelevant when the server's expected life time gets longer than a few days.