Hostile Mobs interaction with Custom Mobs

+Preface
+I create addons and I created Guards for villages. I have not changed hostile mob functionality at all. I have not changes, overwrite, or edit any of the mobs. 

+Problem
+When my Guards attack a hostile mob, the hostile mobs will then target each other. I do not apply effects. They just use swords, axes, and crossbows. 

+To further clarify
+If my guard attacks any mob they will then attack the same type or other hostile mobs. For example: If my guard attacks a vindicator all the other vindicators will then attack that vindicator.