Nice seeing some valid points risen ^^.
Thank you for reminding me about that dude, been ages since I went there. Although he is kind of a “joke” character so I dunno how “serious” they were with his race/class lore explanation.
Regarding the forsaken, I think it is a REALLY big stretch, even on the level of undead paladin.
What I mean is that there are undead paladins in game, although they are considered a “hero” race/class combination in relative terms. What I mean is that the rules for becoming an undead paladin are so HARD, that players character cannot fulfil the criteria and just some extra powerful NPC managed it.
Something akin to that might be happening with shamans or you might be right and be something that just seems alien to us.
Generally speaking, as long as there is a good lore explanation in universe, I am ok with anything