From publisher blurb:
While some spend their time with a single companion to train them for combat, you spend your time to train multiple companions to work together! With the assistance of multiple companions, you command the battlefield. You command a group of smaller companions rather than a single stronger companion. Where a ranger might learn to hunt with just one wolf, you hunt with a pack of multiple smaller wolves to take down your prey.
With group companions, you command a group of 4 or more animals to fight alongside you in combat, using unique support actions and advanced maneuvers. In addition, you will find new equipment that connects your companions together, expansions to animal form to add the badger, boar, and horse forms, and a dromaeosaur option for dinosaur form. You can summon a unique allied animal to fight alongside you but also summon troops of animals of various sizes!