This idea is off the wall and will probably never happen, but just throwing it out there.
What if we had an event (maybe a solo event) that was focused on defense instead of attacks? Here is how it would work:
You are given a fixed amount of resources to build a base corresponding to a certain dragon tier
You build the best layout you can with the resources and buildings you have available
You press a ‘done’ button and an AI dragon (like summon warrior) with attack power corresponding to the current tier attacks your base
If you successfully defend, then you can move up to the next dragon tier with more resources and a tougher dragon to defend against.
It would be like Temple Raids except defending instead of attacking.