It's nice to see them all presented by first appearance like this. Although...why are Reimu and Marisa with the Imperishable Night crew?

id guess because thats the first time they're enemy characters

Yes. They're Stage 4 bosses, depending on which team you picked: Reimu for Marisa/Patchouli and Sakuya/Remilia, while Marisa for Reimu/Yukari and Youmu/Yuyuko.

Actually, one of the main reasons I played for Reimu/Yukari all the time was "Marisa is fucking hard, but Reimu is absolutely ridiculous." It's definitely more about picking your poison than selecting a team.

Also, PCB staff is missing Lily White. (And Cirno, but that's because she already is in the EoSD one).

Yeah, Lily Black omission is acceptable, since it's not really a new character but Lily White dressed in black, but Lily White should be.