New units. Their discussion and selection of upgrades.

It would be wiser to distribute them as follows: if the hero is an attacker, they need to recruit Death Dancers, Nymphs, Forest Archers, and Mountain Ents, the rest is a matter of taste. If the hero is a defender, then Wind Dancers, Ancient Ents, Nymphs, Forest Archers, and Archdruids (first upgrade) are needed. But if the hero is a mage, then this combination is suitable: Wind Dancers, Master Archers, Ancient Ents, Battle Unicorns, and Dryads.

Added 4 minutes later
In any case, dragons should be Crystal Dragons, due to their chain lightning attack. For an attacker, Death Dancers are useful due to their combat skill, which allows them to defeat significantly more enemies than Wind Dancers. And in the case of a mage, Master Archers are essential due to their ability to push back enemies on the turn order scale (especially useful against archers, mages, and strong damage dealers).