I think (just my personal take) the difference or why you guys aren't finding a middle ground is that western versions encompass BOTH stag & vixen AND cuckold setups of a range, whereas nts is kinda in the middle. If I had to graph them where the axis is some kind of 'dominance' or 'autonomy', it'd look like this:
View attachment 5536017
IMO, you're both right, but talking about different areas. SinisterPortal is talking about the extreme lefthand region of the cuckold spectrum, which I'd agree with, you don't see things like "bbc fucks wife while cuckold sits in a chastity cage then licks her soiled pussy" in japanese stories.
When CursedByAll is talking about the western positive outlook on sharing, he's talking about the right hand of this chart. (or even the left side, but with the understanding it's used solely as a bedroom fetish, not some backdrop for one's entire life like he's a loser in the bedroom).
Obviously I'm biased for western games having made this thread and all

- while I recognize some western stories do go into hard cuckold, others stick firmly on the right. With japanese nts narratives, while the reader can be confident it won't go into extreme submissive cuck territory, it also almost NEVER goes into "cool guy mc" territory. Usually I see him being mopey, introverted, introspective, and I can't relate to that.
If there's a concept I'd accuse of being totally foreign to japanese stories, it's levity and a general "joie de vivre". Everything's so heavy-handed and neurotic.