Found some evidence that proves your case actually:
Originally Posted by Wired
Of course, thatís not all thatís changed. Since the release of Doom 3, the studio has grown significantly. Around 60 core developers are working on Rage, three times as many as on Doom 3. Even fewer worked on previous games. On the technical side, the team is also dealing with multiplatform development for the first time, as Rage will be available on the PlayStation 3 and Xbox 360 in addition to the PC. .
Just wanted proof and not hearsay.