>Why should a storm
>giant ranger attack a paladin unprovoked and without remorse?
>If you want to do that, go be neutral or evil.

You're making some underlying assumptions here. Namely, that a storm giant ranger should "care" about killing a paladin, while he needn't "care" about killing, say, a duergar warrior. Presumably because the duergar warrior is evil (i.e. has a red aura).

Does that make sense? Do you really define "good" as, "cares about killing people with a golden aura, but can slaughter red aura folks without remorse"?

If you do feel that way, then I have to ask: Why is "has a red aura" the only valid criterion for remorseless killing? Why not "is a defiler"? Or "uses magic"? Or "is a criminal"?