IMO, if you count EE's, you should count olive eggers. EE's are technically any bird that lays a blue egg. Now, the blue gene is apparantly dominant or co-dominant, since you can breed a brown layer to a blue layer and get olive (mix between blue/green and brown). That means that you can breed the Amerucana to a silkie, then breed the offspring to another silkie, and then probably another generation to a silkie, and still have the blue egg. It would definately not be an "off color Amerucana", but it is still an EE. Not to mention that an olive egger could be more of an Amerucana/Arucana than an EE, because it could just be an Amerucana/Arucana bred to a brown egg layer.
EE's and OE's are almost in a class of their own. They're not quite as "low ranking" as a mixed breed.