Does Rom 5:19 prove the Protestant doctrine of Imputation?

Saint Paul says: "By one man's disobedience many were made/appointed sinners, so by one man's obedience many will be made/appointed righteous." (Rom 5:19). Some Protestants claim this is an important proof text for their doctrine of the Imputation of Christ's Righteousness, because here Paul speaks of believers being "appointed righteous," which they say is different fromactually being made righteous. I want to address that claim here, because it isn't as strong of an argument as they think.

Several years ago I was reading Reformed Baptist pastor John Piper's defense of Imputation of Christ's Righteousness, and I recall he had commented on this very issue in his Protestant apologetics book "Counted Righteous in Christ" (available for free on Piper's own site here). Piper explains his interpretation of Romans 5:19 on Pages 108-109, which I've trimmed down for length but kept the essential parts: