1) That which is definitely designed. 2) That which is definitely not designed. 3) That which is probably designed. 4) That which is probably not designed. 5) That which may or may not be designed but which we just cannot tell.
Unless we can recognise design somehow I fail to see how your argument can hold any water at all. So let's see if we can define a means by which we can recognise design as compared to lack of design in nature.