By clash, I mean whether they can have the same value? That is can there ever be a situation that both changelog id and issue id have the same value within an organization?
It seems to me that this is possible since they are some form of auto-incremented numbers and I don't see how Jira could 'reserve' a number range for issue ids that will not overflow at some point unless those ranges are allocated in chunks and dynamically. Can someone clarify please?