Different Entities that call for help

Couldn't find any answers about this, so here's my question:

How do I create an entity that will call for help from other entities of its type and also a different kind of entity? For instance, how the piglin brute is hostile but will also make all piglins hostile. Both of the mobs are to be neutral but will become aggressive if attacked, and both of the entities will attempt to attack the player. How could I go about implementing this?