@ChrisRichner I am in a very similar situation and currently building a docker swarm cluster. As a replacement for argocd I found swarm-cd. It's by far not argocd but the main function, deploying from git, is there.
https://github.com/m-adawi/swarm-cd
It also supports encryption of docker secrets via sops.
https://github.com/madic-creates/swarm-git-ops

