My take? Of course they can. With the exception of say some divine classes who have vows against associating with certain alignments, people often do in real life and in fiction. You can be friends or family with people of radically different views than yours as well.
Let me give you a recent media example, the character of Joss Whedon's Firefly. You'll hardly ever get a more diversely aligned crew anywhere.
Mal, Chaotic Neutral leaning to Good
Kaylee, Neutral Good
Book, Neutral Good
River , Chaotic Neutral (more or less, she is damaged and thus normal CN tropes are magnified )
Jayne, Neutral Evil (he'll sell out people for money and is fundamentally selfish)
The bad guys in the show
Alliance -- full spectrum of lawful, mostly Neutral or Evil with a few Good guys even ....
Jubal Early -- Chaotic Neutral
The Operative - Lawful Evil
Nishka -- Chaotic Evil
YoSaffBridge -- Neutral Evil
The Blue Hands -- Unknown, probably Lawful evil
Patience-- Probably Neutral
And in case anyone asks, the Reavers don;t really have an alignment or a world view. They act Chaotic Evil but as they have no free will to speak of, they are more or less Zombies and don;t count.
My favourite role-playing games - Apropos of nothing, here is a list of my favourite role-playing games... *Mythras* (formerly *RuneQuest 6 *and Mongoose's *RuneQuest II*...
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