I’ve used 3 Raid strategies in my time playing this game, and thought I’d share them for beginners.
The first is the classic Attack-Up/Defence-Down. Basically you use a hero like Boldtusk to cast Attack-Up for your team, then use a hero like Tiburtus to cast Defence-Down for the enemy, then slice and dice!
The second is Mana control. Here you try to stop the enemy from firing by limiting their mana.
Lastly, Proactively managing the Defence (my current strategy). This is a bit more complex, but basically use Malosi and Bai Yeong to prevent damage occurring to your team.
You can read a more detailed guide for them all here: The Ultimate Raid Strategy Guide For Beginners (Empires and Puzzles) • OLD CYNIC
Hope it helps!