Contrary to what some internet “scholars” may believe, this is not subject to your interpretation.
In self-defense law in general, there is a requirement that the defendant’s action be that of a “reasonable person”. This term is used throughout ARS Title 13 Chapter 4 in every justification for use of force and it’s also found in the Jury Instructions.
The idea of a reasonable person is not based on a real-life person but is a work of legal fiction.
The concept of the “reasonable man” has never been more than a way of explaining the legal principle that even under provocation, people must conform to an objective standard of behavior that society is entitled to expect. A reasonable person is one who acts according to the law, and ethics of society and culture at the time. A reasonable person seeks to avoid risks, deescalate confrontations, use the least amount of force required, etc.
The elements of reasonableness are sometimes legislated into law, which is why we seek out the elements listed in the justification statutes first, then the jury instructions give some more insight. After that it’s left up to the courts to establish case law, expectations, and society as a whole to bring about a degree of reasonableness. Much of the case law on this topic is borrowed from our friends from across the pond, as well as our own case law regarding the torts of negligence.  
Who decides if your actions are those of a reasonable person or not?
The jury makes that decision, weighing the facts of the case as presented in court against this concept of reasonableness. They are given jury instructions in which to guide their decision-making process. They also most certainly take into account their opinions, which are brought about and influenced by society as whole. Reasonableness, is closely aligned with righteousness, which is the quality of being morally right or justifiable.
This is why the Elements of Deadly Force have been taught to police and civilians for decades. They are the proven framework for articulating the belief that deadly force was immediately necessary and reasonable to the jury. 
*This is provided as a Legal Information Resource and should not be treated as legal advice.
1. Bedder v Director of Public Prosecutions, 1 WLR 1119 (1954)
2. Regina v Smith, 4 AER 289 (2000)
3. Baltimore & Ohio R. Co. v. Goodman, 275 U.S. 66
4. Brown v. Kendall, 60 Mass. 292 (1850)
5. The Oxford English Dictionary. (2020)
6. People v. La Voie, Supreme Court of Colorado, 395 P.2d 1001 (1964)