"If there are no copies in play or set aside, advance."
This wording confuses me, it feels like if they wanted this act to advance when all broods everywhere are dead, they would have stated this as "no copies in play AND set aside". Therefore, if there is a single brood in play and you defeat it before any other spawns (even if there are still broods in set aside zone), you get to advance the act.
But this doesn't feel intended to me. Waiting for broods to spawn doesn't feel correct either.
What's the correct rule here? English is not my main language so I could be interpreting this wrong. Using or/and in a sentence like this would mean different things in my language, but it could be a simple grammatical rule in English? (using or instead of and in a negative structure maybe?)