When we talk about guardians, we are usually talking about the roles of police officers. A police officer is a servant who defends the public from threats (Guardian) while also having the courage and skill to fight in battles (warrior). The fact is police officers are both guardians and warriors and more.
The police badge is symbolic of the medieval knights, who were both warriors and guardians. The badge a police officer wears on his or her chest represents the historical knight's coat of arms which identifies the knight and allegiance, much as the badge represents the police officer's sworn oath to serve and protect (Guardian). The police officer's badge worn over the left chest is representative of the medieval knights who wore their coat of arms shield on the left arm, protecting their heart while leaving their dominant hand to fight (warrior).
The law enforcement officers are "public servants" by design. A police officer is a servant who protects the public from threats (Guardian) while also having the courage and skill to fight in battles (warrior).