Add Unique Sequence Number to Child Model/Resources ( in Nova, preferably)

Using Nova, my users can create a Model/Resource called Workflow and assign many Component models to it.

I want the Nova User also to be able to assign a sequence integer to each Component in a workflow_step field.

As an example, Workflow-1 has three Components: Component-1, Component-2, Component-3. I'd like the User to be able to assign an order of sequence like the integers on the left below so I can then display the Components in that custom order:

1 -> Component-3
2 -> Component-1
3 -> Component-2

I can make a workflow_step field available easily enough, but I can't make it unique because other Workflow models will also use 1, 2, 3, etc.

Can anyone give me any pointer about how I should implement this either on the Model or the Nova Resource?

Thanks!