To DJ:
Surely with a 2-bladed teetering head, there is still a coning angle from preconing and from blade flexing, so whenever the disc is tilted away from the mast axis the C of G of the blades must move radially, causing the blades to try to lead and lag?
For example, if the disc is tilted forward, wouldn't the front blade's C of G move outwards from the mast and the rear blade's move inwards, no matter what sort of hinge arrangement the aircraft had?