I get the impression that Nomad was never particularly alive to begin with, which is a shame since it seems better designed. But it doesn't have that "ZOMG Google has blessed us with the secrets of the borg" that DevOps crave.
Nomad was my choice for queue centric workloads, but it doesn't seem to fit the webserver / long living services as good as Kubernetes. I'm not sure, but I would think you could run Nomad and Kubernetes on the same servers, sharing the Docker runtime.
If you run two schedulers they don't have a correct view of available capacity. You can use Mesos as a meta-scheduler but that introduces more complexity.