Universal Rule.
If there are at least 3 models with Holy Triumvirate on your Army List, these models can all select spells as follows:
• Wizard Apprentices: select from the Learned Spells 1, 2, 3, and 4 of their chosen Path.
• Wizard Adepts: select from the Learned Spells 1, 2, 3, 4, 5, and 6 of their chosen Path.
• During Spell Selection, each Wizard can choose to select one Learned Spell fewer than usual and to select 1 Sacred Plague instead.