Shrews deal 73 damage to Venomous wyverns.
Warlords dampen 23 damage with Tribal spirit. (29 spirit lost).
Lizard assailants deal 10 damage to Warlords.
The problem is crystal clear. Shrews attacked Venomous Wyverns who weren't standing adjacent to Lizard Assailants, hence no Assault should have been performed. Instead, the Lizard Assailants performed Assault on Warlords who weren't attacked by Shrews at all.