how to display entity references as numbered list?
Its pretty simple, in this example I will use title instead of an entity reference field, but it's the same process. 

Step 1) add Global: View result counter as a field. 



Step 2) Uncheck create label, and checkmark hide from display. 



Step 3) Re-arrange so your counter is above your entity reference field.



Step 4) Re-write results and use replacement patterns to format your title field.