jcjeant;
You know as well as I do that the sidestick takeover buttons are for that very purpose - when you need to either take control momentarily, (to avoid dual sidestick inputs), or completely locking-out the sidestick on the other side due to a more serious problem, (pilot incapacitation, for example).
In the control column case IIRC you can break the elevator control-cable "channels" to separate control columns in a B767, (Egyptair case) and in the L1011. Other than that, (DC8, DC9 case), the "winner" will be he who, for whatever reason in the moment, is the physically stronger.
I'd take the sidestick lockout solution over the other solutions.