That isn't really the same thing. The Chiefs didn't have an MVP QB already, and Luck didn't have an MVP season on his resume.
A more apt comparison is, let's say somehow the Packers are the worst team in the NFL this year and get the #1 pick. Should they take a QB, or trade that pick for 4 1st rounders, assuming there was a QB deemed worth that? I think most would say keep Rodgers, and rebuild the team with 8 1st rounders in a 4 year stretch.
The Colts weren't really a bad team when they got the #1 pick in 2012, they were a decent team, that had a year starting a well past his prime Kerry Collins, and Curtis Painter. They were very likely going to be a playoff team in 2012 with Manning.
I'm not disparaging Luck by any means, just revisiting a thought I had in 2012, and how things might have gone, with Luck only playing 3(really 2) seasons more than Manning.