Threading instances of an invoked runbook

Hello Everyone,

I am currently working on a set of runbooks to complete tasks associated with an approval process.  I have one runbook that adds an approver to a service request based on user input and a database query.  At the end of that runbook I am invoking another runbook that sets the status of the service request to pending approval.  The issue that i'm running into is that i'm not getting dedicated threads for each instance of the runbook that sets the status.  If I submit 5 requests the runbook that assigns the approver runs 5 instances, but the runbook that changes the status runs one at a time.  I was under the impression that the runbook that sets the status would start a new instance with each invocation. The screen shows what i'm seeing the scorch console.  

Any advice would be much appreciated.