I have a usecase where I have a custom statefulset, which I need to replicate as specified by the number by user, the same way deployment are scale up and down with replicas in kubernetes. And for that I am thinking about creating an kubernetes-operator e.g memcached-operator, I need your suggestions, would it be right approach or anything simpler can be done to achieve this goal, and I need to manage those statefulsets as a single deployment or unit as per say.

for example this is what i want to achieve

apiVersion: "sts.example.com/v1alpha1" metadata: ... units: 3 replicas: 2

here units represent the number of statefulsets and replicas represents the number of replicas in each statefulset.