Adam had no life to impart, lost his righteousness, and was incapable of saving his wife. Not only didn't he die for her, he was incapable of dying for her.
Moses is a type, but was not able to lead them into the promised land.
Joshua is a type, but did not give them rest.
The offerings are a type, but the blood of the sacrifices could not remove sin.
David is a type, but could not build the house of the LORD.
John is a type, but his baptism did not save.
Adam doesn't need to be Christ in order to foreshadow what Christ would do.