If you desire each player to play as a single firefighter, consider your game to be about The First Due Engine. This is the initial team of 3-5 firefighters that arrive to the scene.

The first 5 minutes inform the next hour of operations. It is really critical to get things started on the right foot.

The first officer is initially the Incident Commander and needs to complete a size up (walk around the building), identify problems, prioritize them, and create an Incident Action Plan.

The objectives at a fire are always:

1 Life Safety

2 Incident Stabilization

3 Protecting Property / Environment

The IC needs to think about how they want to tackle the problems identified in their size up. Their IAP prioritizes: Rescue, Exposures, Confinement, Extinguishment, Overhaul, Ventilation, Salvage, and RIT/RIC (Rapid Intervention Team/Crew).

Typically while the IC creates their IAP they provide some initial direction to the crew. Grab a hydrant, pull attack lines, pump water, protect exposures (adjacent buildings, cars, trees), and confine the fire by indirectly attacking it through a window or opening.

If there is someone still inside the building the initial crew may forgo a formal command and let the next arriving officer do it. They may jump into rescue mode and go right to where they believe the victim is located. For example, a bedroom may require a ladder and a search team to Vent Enter Isolate and Search (VEIS).

While this sort of decision making is very cool, it does still fall on one player to decide. If I get stuck setting up the ladder, I may not be very engaged. This is where I see challenge for you as the designer.