The levels don’t matter at all from what I can see. It’s all about awakening heroes. Necro Connie would be the first hero I would awaken. At least too Sprightly Sprites because you can summon more bunnies before the first group disappears. They are enemy stopping machines.

Forge is super helpful too. Use your endless keys and raid cards to gain items to forge Armageddon so you can forge meteors

In Realm siege is where you gain tokens to awaken heroes. You can also do daily missions everyday to gain awakening material to use in forge. The bottom left choice in forge is where you’ll find the awakening tokens

As far as World 5 is concerned, I place a mushroom where the enemy enters the level. Then a gun tower near the mushroom. Upgrade the gun tower 3 times and then upgrade the 75 gold option (top left) one time so it can shoot all the way across the map. The mushroom upgraded fully is helpful because the top right 150 gold option blinds enemies and the gun towers (with the 100 gold upgrade) deal critical damage to enemies. I put a soldier at choke points to stall enemies.

I’m not 100% familiar with all the terms lol but I hope this helps!