Board Thread:Questions and Answers/@comment-11700680-20170920202000/@comment-26366865-20170920225027

http://kancolle.wikia.com/wiki/User_blog:Hayashi_H/Grinding_DDs_and_CLs_on_3-2A

Since 3-2A with DDs is morale-dependent, your best option for mass training is keeping a couple of different fleets and sortieing to 1-5 while they regain morale. You can run 1-5 at any HQ level as long as you have a single ship capable of OASW.

However, even if you spam these non-stop, there’s no way you’ll be able to train that many DDs while still having time to stockpile. I suggest trimming down that number to only include the essential ships, and worry about trophies only after you have a capable fleet.