The discussion is acceptable. I would like to point out that a categorization of something means that there is a set of traits that are POSSIBLE to exist within that categorization BUT are NOT always going to be there. Yes, there is a set of traits that must be present in order to be in a specific categorization, but the possible traits are just that, possible, not mandatory, in order to be in that category/classification.
Also as someone already mentioned, some traits overlap with certain other classifications and are more probable to be in that secondary category/classification when that happens. Classification and categorization is a topic that many debate over in all subject fields, however understanding what I have laid out in this reply is important in order to clearly see what is going on and helps aid in gaining clarity of categorization and classification conversations.
Please proceed if there is further discussion. This is only to aid the conversation. The main topic was in fact to root out these specifics, so there is no derailment as far as I can see. It seems pretty on topic.