When two SObjects have a one-to-one relationship and one of the objects in that relationship does not have a plural form the resulting DTO has duplicate properties causing compilation to fail. Similarly when the SObject with no plural form has a hierarchical child parent relationship with itself.
EX: Equipment_c has a relationship with Yard_Slot_c, were they both lookup to each other for a 1-to-1 relationship. Yard_Slot_c.java DTO has duplicate properties because both its Relationship *and its Child Relationship are named *Equipment_r.
EX2: Equipment_c has a parent/child relationship with itself causing both the Parent and Child relationship names to be Equipment_r.
**Salesforce allows and handles both these scenarios properly, however the resulting DTO classes do not compile because of the duplicate properties and duplicate getters.
An easy fix would be to always append the suffix List on child relationship properties in DTO.