Honestly, they don't need to take Ballmer's spot -- one of them should take BillG's old spot before all that CEO nonsense. That is, the old Chief Software Architect role, when he used to run around reviewing every product both creating a longer-term cohesive strategy for the software and instilling the fear of instant group dismemberment if you were not thinking deeply enough.

While I personally like Guthrie, Rudder was a one-time personal technical assistant to BillG. That was a role where he basically rode shotgun on a couple years of BillG reviews. And that happened back in the 90s, when he wasn't yet drifting off towards the sunset...