Rigid aveforce/addforce are different

The manual says ‘‘This means that each timestep the total force and torque on each rigid body is calculated as the sum of the forces and torque on its consistent particles.’’(fix rigid)
So why would the results caused by ‘fix aveforce’ and ‘fix addforce’ applied to a rigid body be different?

If aveforce and addforce are applied on a single rigid body, are you sure that the results are different? I would guess that differences would only occurs in the case where there are several rigid bodies…

I think you can see what I mean. For one rigid (rigid/nve), if you replace aveforce with addforce, the results will be different.