All members: 18/20 clears / Avidity grimoire (all clears less those who's boons do not increase with repeats) (those only the leader uses avidity others use dilligence)
Player 1(lead): Adjunct 1-5 / Avidity grimoire
Player 2(lead): Assistant 1-5 / Avidity grimoire
Player 3(lead): Instructor 1-5 / Avidity grimoire
Player 4(lead): Associate R 1-5 / Avidity grimoire
Player 5(lead): Researcher 1-5 / Avidity grimoire
Player 6(lead): R Emeritus / Avidity grimoire
All members (-Lead): Dilligence Grimoire
That way leader always does the boss w/ some lv2 buffs (level 3 if you repeat 18 clears a 2nd time with avidity)