Valkyrie attack strategy: combo of Valkyrie, Witch, Hog Raider, Healer & Jump spell1. About Valkyrie
As you know, the recent update changed the Valkyries attacking style. Now they specifically target between buildings, allowing them to destroy many buildings at the same time, very cool . Now, we can use them for many roles such as: killing CC troops/heroes (plash damage can kill them fast), or tanker, building destroyer, ...
2. Combo your troops
Troops: ​13 valkyries, 3 witch, 8 wizs, 7 hog raiders, 6 WBs, 3 arcs
Spell: 2 heal, 2 rage, 1 jump
CC troops: all hog raiders 
3. Cost
Walk: 13 valks (2080) + 3 witch (1050) + 7 hogs (455) = 3585 dark
Elixir: 8 wizs (32.000) + 6 WBs (21.000) + 2 freeze (70.000) + 2 rage (66.000) + 1 jump (31.000) = 220.000 elixir
SUM: about 3500 dark + 200.000 elixir 
4. Training time
About 1.5 hours for completing this strategy