The smaller-town first responding officer follows a case from patrol to prosecution. They gather evidence, prepare warrants, perform interviews, and present it to the district attorney. It's their case from 911 call to courtroom.
One of the mottos of the International Law Enforcement Educators and Trainers Association (ILEETA) is "When safety is taken for granted, take injury for granted."
"The will to survive, to survive the attack, must be uppermost in my mind. Therefore, preparation and not paranoia is the key to my survival. To survive I must be aware, be alert, be confident, be deceptive, be decisive, and be ready. I must expect the unexpected and do the unexpected."
Whenever you arrive for mutual aid, you're the visiting team. Everyone has different ground rules. Another department arriving on mutual aid may have a more stringent or lackadaisical policy. Compare their policy for deployment to yours.
Training in real-world conditions is the key. Get outside in the hot, cold, dark, and whatever weather you have to operate in. Realism begins in training and not in make believe.