If the Colts were to listen to Archie Manning, Andrew Luck might not get drafted by the team because he thinks Luck wouldn't fit well with Peyton nor does he think both of them would want to be on the same team.
Although his basis for this is due to him being on the same team with Luck's dad when both played in the NFL and said it didn't work out well.
http://espn.go.com/nfl/story/_/id/73...ot-good-either