Calling them idiots? This coming from a person not understanding the job they are performing. The two on the roof are relieving pressure in the building as well as creating ingress and egress points, ingress for the water and egress for the fire pressure.

Building fires create a serious amount of pressure due to the expanding air in a very confined, and pretty well insulated, environment. This is the same actions you see firefighters breaking out windows to expel a large portion of said pressure. It also allows a fire to expand in a more controlled and less volatile way (see: explosive backdrafts).

The guy using the 'poker' is looking for structural weakness, both for the safety of the crew on the roof, as well as the 'cutter' to have the most direct access to the higher 'heat areas'.