I think I know the answer on this, but coming to the community to see if anyone else has any ideas.  

We have many custom workflows based on the service item selected.  We have a general workflow that will update the details of a request (priority, impact, urgency, etc) and assign it to a group for all other service items that are not part of any other custom workflow.  We have a custom object table setup for all our service items that list the group to assign it to and approvals that may be needed.  

If a request comes in for a service item that has a custom workflow, the ticket goes through both the custom workflow and the general workflow, causing issue with approval routing.  The only idea I can come up with to prevent this is to exclude those service items that have a custom workflow in the general workflow.  

Any other ideas to prevent this?