Different nuclear conflict scenarios would differ hugely in how harmful they'd be in the near-term and in how much existential risk they create. In light of this, it'd be useful to have a clearer sense of the likelihood that nuclear conflict would involve many attacking and attacked countries, rather than just one or two.
(For example, the likelier it is that a conflict involving North Korea would escalate to involve a conflict between the US and either China or Russia, the more it makes sense to prioritize reducing the chance of such a conflict or such escalation, rather than focusing more strongly on only conflicts that start out involving multiple states with large arsenals.)