User blog comment:Dethyl/Thoughts on preparations for large scale (and difficult) events/@comment-26701465-20150917112932/@comment-25174240-20150917151554

Hi. thanks for your comment.

20-30 DDs is a rough number, 20 is roughly enough for a 6 or 7 map event. 30 is a comfortable level for critical spares.If you recall, Kikuzuki of the Mutsuki-class helped to get easy routing in E-1 for summer 2015. When the event started my Kikuzuki was near level 80. Reason being that she's Mutsuki class, low resource consumption and thus great for expeditions every day.

Typical priorities involves more than just high luck destroyers. I would say, every destroyer that can get kai ni should be pushed up. If you count those that the better ones without kai ni such as Shimakaze and Yukikaze, you'd have about 15+ DDs, the rest can be from any that you've been using a lot and is high level.

Evasion and accuracy are level dependent, so even what is considered a mediocre destroyer like Z1 or Z3 can be used to devastating effect in events when they are level 80+. A DD is always going to be a DD, meaning that she has low hp. A level 99 Yuudachi will still drop to taiha in a single good hit from a flagship type abyssal BB. These days with searchlights on lucky ships, skilled lookouts on lower luck ships and another ship launching star shells, even less lucky DDs can hit cut-in with some regularity at night.

Short answer to your question, any DD that you have left that is relatively high level will do. You never know who will help you get easier routing in the next event. So a 1 or 2 from each class is useful.