Currently, the Kiali code assumes workloads are always Deployments.
But workloads are not always Deployments. Workloads could be replica sets. Workloads could be pods (if the pod is outside of any controller like replica sets). Presumably, workloads can be anything owning/controlling pods or the pods themselves. For the code that determines workload names, see: https://github.com/istio/istio/blob/release-1.0/mixer/adapter/kubernetesenv/cache.go#L180-L214