Final answer:
Brigadier General Irwin could be nicknamed "The Fighting Doctor" due to their combination of military service and medical expertise, demonstrating acts of courage and commitment in both fighting and healthcare during wartime, similar to historical figures such as Dr. LeVasseur and Dr. Edward.
Step-by-step explanation:
The nickname "The Fighting Doctor" is typically attributed to a military figure known also for medical expertise and bravery under fire. Various historical accounts demonstrate that medical professionals serving in armed forces often worked under extreme conditions, provided critical medical care, immunizations, dealt with enemy bombardments, and performed their duties with as much valor and dedication as combative personnel.
These attributes are symbolized by those such as Dr. LeVasseur, who worked tirelessly even under German invasion, and Dr. Edward who survived the perils of wartime service and was honored by the French Government and commemorated by the University of Toronto for her service.
A figure like Brigadier General Irwin could be called "The Fighting Doctor" because of a dedication to military and medical service, often shown through exemplary acts of courage and commitment in both fighting and providing healthcare in the theater of war.