To use the wizards effectively during attacks, it should be used in combinations with other ground troops that attack the enemy’s defensive buildings first such as giants and golem.
In using this fatal combination, you need to deploy your giants or golem first.
Giants and golems distract the defensive structure making them target them first.
When the defensive structures starts to target them, you can drop your wizards behind your other troops.
Wizards can cause great damage to enemy structures but can’t take much in return. That is why they should not be your first line of troops when attacking.