Is cost code field required for Job Cost?

Oracle document 1549454.1 states that the subsidiary is optional for a G/L account but the cost code is required for each job cost account.  We currently use job type business units for operational projects using the same chart of accounts as the primary operational profit/loss BU.  Since the primary P/L BU only uses objects (no subsidiary set up) in their chart, we would like to setup the job type BU chart using the same setup where the cost type = object and leave cost code blank.  High level testing suggests this won't be a concern but I'm wondering if there might be