The daily events in Slot B are fairly grindy seeing as your attacks refresh every 5 minutes. However, intelligent attacking can mitigate the grind.

Follow these simple rules:
1. Only attack people with >= 10,000 points as they have already received all of the event's point rewards.
2. If there is no such person, attack only people who are sitting at a point threshold with no defense shields.

Do NOT attack people who are crossing between point thresholds. Not everyone is going for rank, and you are wasting valuable event points. You're not going to get rank awards unless you get 10,000 points anyway (and have put forth the cash for defense).