Cattle - make sure two containers in service are not on the same host

Say that I have a stack containing a couple of services, and one of the services has 2 running containers. Is there a way for me to indicate to rancher that I do not want these running on the same host? Some kind of anti-affinity rule? I realise I can tell Rancher to run an instance of the container on every host in the cluster, but that’s not what I want - I just want to make sure the service is running on more than one host at any given time.

https://docs.rancher.com/rancher/v1.3/en/cattle/scheduling/#example-1

Swwet ! Definetely bookmarking that page!