it was called rough justice and it tended to work.

Whether it works in a civilian law-and-order context is questionable but arguable. But in the situation of a foreign occupation and civil disturbance/insurgency all the evidence is that the main effect is to recruit for the other side, and to generate communal support for the people involved.

The use of force while capturing people, or even when dispersing them in some situations, can hardly be avoided, and I haven't suggested that it can be - but it is not the same thing as beating up prisoners who have been captured. I think most soldiers recognise and value that distinction, and would hope that it would be observed if they ever get taken prisoner.