At this point, I would rather have a closer look at either Nomad or k3s for smaller clusters.
Swarmkit is what is being used in production and is fairly popular.
https://www.digitalocean.com/currents/june-2018/
"While @kubernetesio was most popular overall, the smallest companies (1-5 employees) use @Docker Swarm more often (41 percent use Swarm vs. 31 percent that use Kubernetes)."
Last month they released https://github.com/docker/stacks for Swarm.
Also, every industry survey I've seen in the last year on orchestrator uses shows increases in overall usage of K8s and Swarm, which I consider the better measure of a project's health. (CNCF, Digital Ocean, F5, Sysdig)