I think Luck has the potential to be very good- great even- I just wouldn't ever, under any circumstance bank my whole franchise on one player out of college. It never works out.
John Elway was traded for two 1sts and a backup QB (who was originally drafted in the 4th round). He went on to lead the Broncos to 5 AFC Championships and 2 Super Bowl titles, including a Super Bowl MVP.
Eli Manning was traded for two 1sts and a 3rd. He went on to win the Super Bowl, including a Super Bowl MVP.
You should clarify the definition of both "banking the whole franchise" and "working out." I'd say that two 1sts and a 3rd worked out quite well for NYG. Is three 1sts and a 3rd too much? Three 1sts and a 2nd?