How to clean up too many relationships?

Good morning Bob,
If the reference field is not scalar (ie. a formula or a lookup field from another table), then you are not going to be able to summarize that tables data if you change the relationship.

If you have a way to make it into a scalar field, then cleaning up the relationships is just time consuming. Then open both relationships and you can reassign each of the lookup fields and summary fields from one of the relationships. In the pictures that you showed it is unclear what fields are tied to which relationship. It seems like Related Hardware is an auto-generated scalar field inside of Assignments and the Hardware - Asset Tag was added at another point.

I don't think that QuickBase is going to be breaking that functionality any time soon. They allowed summaries against calculated fields for several years, and a lot of companies still use those legacy designs. It is relatively recently (within last 2 years) that they started preventing new summary fields in that situation.  There is nothing that is going to prevent you from having multiple relationships between the same tables. I had 50 scalar fields that were references to the same parent table. I needed to create 50 dropdowns for an order form. I generally will have 2 relationships to the same table. One formula and one scalar. 

Thank you,
John