Yes, delegators share the rewards determined by their delegation.
Curators are rewarded individually. The system works with a queue, and the bot votes with a weight depending on queue lenght every time its voting power is at 100%. This was made to maximize creator rewards, but also prevents the issue you mentioned. Known high reward posts will have automated votes on them long before the post reaches the top of the queue. To maximize their rewards, curators have to find posts that have not yet been voted on but have the potential to draw more votes with the visibility boost our vote provides.