Proletarian revolutions aren't going to happen simultaneously, and they won't always be successful. International revolution is most likely to start within one state, or a cluster of states, after which their main goal must be to expand the revolution, lead by example and provide guidance or military aid for states that are also undergoing revolutions. This isn't guaranteed to succeed though, as seen in USSR where most revolutions abroad got extinguished by their national bourgeois, it having to take survival measures to preserve itself and alleviate poverty due to its isolation, then eventually succumbing to counter-revolution and subsequent stalinist nonsense.

Revolutions cannot be delayed or for them to be "left to simmer" until perfect conditions arise, since no such thing can exist given uneven developments, different levels of influence national bourgeois have on proletariat and just different historical conditions in general. Proletarian revolutionary crises themselves are largely spontaneous, they happen with or without bodies of power (like councils, parties, etc) organizing them, and all these bodies can really do is choose whether to act upon the revolutionary crisis or not, as in whether to agitate and shape the existing class consciousness to be a fully communist one and/or taking leadership of the movement entirely and ensuring revolutionary success, etc. In other words, they can merely react, not will the revolution into existence.