Since Sel wont answer the tough question how are these 5 ranked respectively?
I'd rank Touka, Karin, and Noriko as the top 3 easily. Probably in that order.
All 3 go out of their way to help whoever, especially the homeless:
I'd also put Uta over Futaba. Futaba is nice, but in a pushover kind of way. Both are willing to help those they care about, but Uta tried to stop Yumi's bullying, and slapped Nodoka for Io. I don't see Futaba standing up to anyone, for anyone besides
maybe herself, not to say she wouldn't speak kindly about those she cares about.
Although, certain things make all of their kindness a little sour. For example: Noriko let's a predator and molester do whatever he wants, which is basically what Karin is doing now, except Noriko knows he's gone for younger. This definitely brings into question their altruism.