sadisplay's got problems with polymorphic inheritance
In my model, I have two classes Contest and Course which are polymorphic identities of Event (https://github.com/moschlar/SAUCE/blob/develop/sauce/model/event.py).
sadisplay only finds the alphabetically first name, maps all the ForeignKeys to that node and then displays one single inheritance arrow (see attached image).
I'll work around it by only including the parent entity Model in the list for describe, but if you happen to implement this anytime, I'd be interested! ;)