Used in war is preferred. Find a reasonable target (for th 6-7)
When found a target, use the archers to lure away CC troops and kill them with archers and lighting spell. (If necessary use few wizards incase the killing takes too long)
Now you need to find a weak spot. The weak spot would be a good place for you to place the wallbreakers. The weak spot is where you can place the wallbreakers close to the wall as possible. BUT only place them where you can get into some defense.
Now that you have destroyed walls and you can break into the enemy's defense place the giants as close to the hole as possible and behind the giants place the healer.
Now it has to go a little faster, so quickly deploy all barbarians spread them out and when you have done that deploy the archers behind them as the barbarians will take most of the damage by defenses.
Now you should deploy your healer spell on a group of soldiers (i recommend the giants)
After you have deployed the healer spell quickly deploy the goblins and then the wizards. (If you have CC troop DRAGON IS RECOMMEND CC TROOP place them)
(No execution notes)
Now wait as you will get 3 stars. NOTE: On some th7 you may get 1-2 stars. GOOD LUCK