JSON MERGE coomand needs to change JSON Patch command - json

Question

Basically, I have 3 CR's global,db2 & Mongo. I have to edit these 3 CR's manually to add/enable a service like 'oc edit global, db2 and mongo' then I'll add service details and it works.
But I need to give a single command to users like a patch command. Below is the method which is a normal process
oc edit global
spec:
Global:
backup:
enabled: true
name: backup-name
storageClassName: RWX
size: 500Gi
=====
oc edit mongo
spec:
statefulSet:
   spec:
     template:
       spec:
         containers:
         - name: "mongod"
           volumeMounts:
           - name: backup
             mountPath: '/opt/data/backup'
         volumes:
          - name: backup
         persistentVolumeClaim:
           claimName: backup-pvc
=============
oc edit db2
spec:
  storage:
  - claimName: backup-pvc
    name: backup
    spec:
      resources: {}
    type: existing
In terms of writing patch commands I succeeded to write JSON Merge command as below:
For Mongo:
oc patch MongoDBCommunity staging-mongodb --type=merge -p '{"spec":{"statefulSet":{"spec":{"template":{"spec":{"containers":[{"name":"mongod","volumeMounts":[{"name":"backup","mountPath":"/opt/data/backup"}]}],"volumes":[{"name":"backup-","persistentVolumeClaim":{"claimName":"backup-pvc"}}]}}}}}}'
For db2:
oc patch db2ucluster staging-db2 --type=merge -p '{"spec":{"storage":[{"claimName":"backup-pvc","name":"backup","spec":{"resources":{}},"type":"existing"}]}}'
But above JSON Merge command is replaces/overrides the previous data. So it is not desired method. I see there is a desired way to do is JSON Patch where we can use some operations like add, replace, etc., Need help on writing a JSON PATCH command for the above 3 CR's manual step.