The nice thing about the 737 is that the LH only has the tiller for most operators. So there's no need to let go of the levers as their hand is already there. Quite literally, hand over control, set takeoff thrust yourself, and you're set. None of this lifting hands business. Can I suggest that perhaps the callout such as "Takeoff" should be the cue for CM2 to let go of the levers (if they've taxiied out) and for CM1 to set takeoff thrust if we go down the avenue of 'the Captain has responsibility and the authority to reject a takeoff' to prevent potential turmoil?