Oh, so now at least Manning is a key cog... The Colts aren't stacked with talent, period. they have a handful of players on offense and defense who are above average talents. Manning makes them look way above average much of the time. Collins can't do that, and it's debatable he'll even still be standing and in one piece in 6 weeks... They weren't built to operate absent a talent like Manning under center and running that timing offense and basically calling the shots.
Manning is the hub of that wheel. Absent it the cogs fall apart. Even the defense feels the effect when that happens because their wheel was only designed to keep teams close enough for Manning to close on or to defend a substantial lead once he built one.
Your stupidity in not accepting that is your own issue.