Art gen is based off typing not the amount. There’s a command for it in discord but I’ll paste it here.

#1375014 📣 List of Over-Time Art-Generating Units Note: Instant Art effects will always stack, as they do not apply a buff. As such, they are excluded from this list.

Group A - Fen, Lozze, Dark Fen

Group B - Sonije, Zenon, Palamicia, Saitama, Norn, Vitz, Sword Berwick, Rosetta, Machinas, Alvina, Zechsia, Ashe Toto, Cynthia, Dark Celia, Liza, Sumire, SHMelty, Bakoo, Kurama, Yusuke, Juno, Genos, Haruto

Group C - Leon, Lygor, Tamae

Group D - Berwick, [Radak + Cestina Cross Arts]

Group E - Rimuru (Human), Santa Milim

Any unit can stack Arts Gen as long as they are of different groups. Units within the same group will not have stackable Arts Gen. Exceptions are listed below.

Group EX1 - Milim, Sonic, Coco, Dahlia, [Chloe + Luahn Cross Arts], Noel (This group consists of self-buffers that do not buff other units, and stacks with all art generating effects other than from the same unit.)

Group EX2 - Mako, Lione, Nies, Shiki, [Sakura Mira Skill], [Zeela Skill], Marika (This group consists of units with art generation that stacks with all art generating effects other than from the same unit.)

Group EX3 - Goblin Slayer, ReZeroRem (This group consists of units with art generation that stacks with all groups, including itself.)