Ok listen here guys but if you want a good set-up (at least i think its good) But please try it.
Unit Cards: Skill Cards:
Goblin Lv. 5 Health Lv.5
Black Knight Lv.5 Comet Lv.5
Centaur Lv.5 Zeus Wrath Lv.5
Fire Succubus Lv.5 Hercules Strength Lv.5
Witch (Bitch) Lv.5 Athena Protection Lv.5
Mermaid Lv.5 Meteor Strike Lv.5
Tip: Send you hero in fight and keep backing him up with Comet and Health, and when you have full army and all spells are fully charghed, just rush and then when the big wave comes use Zeus Wrath, Hercules Strength and Athena Protection at once you destroy their army.
This is how i play at least and i think its a good strategy and sorry for long message