I think you got it backwards, "C" is for capacity (useful since (dis)charge current obviously scales with capacity, ceterus paribus) and a 2C discharge rate is

I think you got it backwards, "C" is for capacity (useful since (dis)charge current obviously scales with capacity, ceterus paribus) and a 2C discharge rate is twice the current of a 1C rate. You also need to be careful in your calculations. Battery discharge rates are given in Amps (or C multiples) not Watts because over a cycle, cell voltage will naturally drop. Discharging at 5 Watts puts more strain on an empty than a full cell since the first requires higher current to compensate for the lower voltage. Amps reflect the "demand" better. Your summary is still correct though, there is more margin for degradation in a laptop battery and space for decoupling.