MitD VIII: Everything we know about MITD (but were afraid Tarrasque)

[Windscion]

Sabine ... also helps her friend Vaarsuvius

Assuming that Sabine sees V as a friend is a very dangerous assumption. First, after hearing V talk about how V would use her(V's) power to recover an errant lovers attention, Sabine went and reported V to her boss as a potential target. (Note: she did this after telling V "You're all right, Elf.") Later she provides V intelligence on Vector Legion why? because she wants revenge on Tarquin!
In short, whatever evidence this gives of Sabine's true colors, it does not prove anything resembling goodness on Sabine's part, and hence on races defined by alignment.

Also, I would add to what Keltest says above, even beings of diverse alignment and goals may well cooperate toward some short term goal, like preserving the world against an Eldritch Abomination like the Snarl.