Stef, talked to you about it already in chat, but for anyone else who's wondering!
Dogs, like people, share similar features, but there are always slight variations in how these features are presented. For dogs, there are many things that vary the "floppiness" of the ears, the strength of the cartilage, the thickness, the size of the pinna (ear flap) as a ratio to the strength of the cartilage, calcium intake in the diet, teething (which is related to calcium usage), age, and probably other things that we aren't aware of yet (mood, seratonin levels).
To be honest, the "erect ear" thing is more of a breed standard of AKC and the likes, and not necessarily something that you should be concerned about unless you plan on showing/breeding dogs. With my dogs, I have no control over their ear rigidity. One minute they are flaccid, the next they are erect, Ritz always has floppy ears in the morning, Sadie gets them during afternoon naps.
Whatever Chico's ears look like, I guarantee you will love him either way, and his ears will be a part of his multi-faceted personality!