I would like to refer to this youtube video that discusses techniques to attack Anaguma castle. This youtuber picked examples out of ShogiWars actual plays and compiled them to compact yet very effective format to explain how to compromise the Anaguma castle. Although spoken in Japanese, you should be able to pick up things or two in this 7 minutes presentation video. Enjoy!
https://www.youtube.com/watch?v=qsuREhaZ1tw 7 technique discussed for attacking Anaguma castle by こいなぎ将棋実況