It depends overall what you're doing ie are you connecting Acquia/Widen to Workfront? What are you planning to do in the integration and which direction(s) will information travel? Is there something you already use to find assets as a user that is unique and could translate easily?
A 5 digit number can help but that will limit you to ~100,000 assets cumulatively (assuming you can begin with 00000); is there a unique combo of metadata you can use in concatenation?
