The 05 defense was stacked with future stars. But they were not the same players they would be in later seasons. Unfortunately the offense took a step back and they never returned to the title game.
Biggest losses imo, from 2004 to 2005 was Cody like you mentioned. But they also lost Mike Patterson who was dominant and then of course Lofa Tatupu. Those two with Patterson were huge. And of course Eric Wright (who would transfer to UNLV) he left for off the field issues.