Erin, responding to your 2nd post..
So I see what you mean now. Yes I think its a fine idea to launch a little script, asynchronously, that scans the DnB hierarchy and replicates the structure but uses a different relationship type to form the "Customer Hierarchy". I've done this in the past successfully. I'm quite interested to hear others' perspectives on this. In my experience there are various structures that tend to exist simultaneously, each representing a different business purpose. Often times the hierarchy that is maintained within Salesforce is replicated into Reltio along side the DnB hierarchy, and displayed in its own facet separate from the DnB hierarchy facet. The Salesforce users usually structure their hierarchy to support specific go-to-market sales motions or territories and thus the structure is oftentimes different than the DnB hierarchy which is the "legal" form of the customer's organization. I'm going to guess within the Reltio UI, most Reltio Data Stewards do not author a hierarchy from scratch but likely will only edit an existing one that came from another source like Salesforce, and may do so to fix data issues that came over from the source. Eg. sometimes when ingesting multiple sources you might encounter a "loopback" scenario where an Account refers to itself as a parent. So that is something that might need to be fixed in Reltio and then traced back to a source data issue for remediation. Or oftentimes the hierarchy that came over from Salesforce isn't really valid because the sales rep didn't do enough research or was a bit hasty when creating it, and so the Reltio Data steward might be tasked with doing the deeper research (internet searches, reading articles about recent mergers and acquisitions) to fix the hierarchy in MDM, collaborating with the sales team, and then push the changes back to Salesforce.
Again, interested to hear others' perspectives on this topic
Curt