There is still a limit to how strong Zeke is and, fighting five generals in their [Primal State] definitely includes this. But it is not because he can't finish them all off. In fact, he can win against them but, the aftermath of the fight would probably be too devastating that most of Zeke's quests would fail and, if there's anything that Zeke does not like, it's failed missions in games.
"This'll take too much toll on me." Zeke said out loud, preparing a spell to end the fight immediately without causing more damage to the surroundings.
He [Conjured] monsters right in front of the generals who have just activated their [Primal State]. The summoned creatures touched the generals but, received no response.
From the intel gathered by Zeke, he knows that there is a five second delay before someone could move after transforming to their [Primal State]. They are invulnerable within this time but, it doesn't mean that nothing could be done to them.
