Can Good And Evil Characters Get Along?

[Satinavian]

I think we can safely do without the DnD 3e concept of poison being automatically evil. Those two rogues are equivalent, if stabbing wasn't evil then stabbing + poison isn't evil either.

D&D is full of arbitrary declarations of things to be good or evil.

But it doesn't matter if you agree with it or not. In most editions the poison user of the party is evil, pings as such to detect alignment spells, gets the treatment from Holy word and smite etc.

And this is pretty much a typical example of an evil PC. Most evil PCs are evil in some particular way and if the rest of the group does not care about this particular thing, then there is no conflict. That may be poison use, undead use, demons for summon monster or any of a very long list of pretty arbitrary "Evil" actions. And usually there is no remorse whatsoever.