Alright, so imagine this:

Duty Roulette: Leveling (Beginner) -> ARR and HW Dungeons
Duty Roulette: Leveling (Intermediate) -> STB and SHB Dungeons
Duty Roulette: Alliance Raids (Beginner) -> Crystal Tower and Shadow of Mhach
Duty Roulette: Alliance Raids (Intermediate) -> Return to Ivalice and YoRHa: Dark Apocalypse

Leveling and Alliance Roulettes are split in two: one for the first expansions and one for the later ones (but not the last one). Furthermore, Main Scenario Roulettes are turned into solo duties and the beginner roulettes are the ones who give the big Poetics reward. Also, rework Coils to add them to Normal Raids.