Combining Bag/OrdList?

We have OrdList which does: Provide trees (of instructions), so that lists of instructions can be appended in linear time. And Bag which claims to be: an unordered collection with duplicates However the actual implementation of Bag is also a tree if things. Given that we have snocBag, consBag that implies to me it's also an ordered collection. I wondered if besides of someone having to do it if there is a reason why these couldn't be combined into a single data structure? Their implementation seems similar enough as far as I can tell.