you have just described exactly the idea of limited play I was talking about. Of course, in splinterlands there should be some changes for more auto-battler mechanics and more collection-based related battles, but I don't think it's impossible to implement. There are always some options to imitate it using some tricks for example maverick test server, but from my experience, people are always more interested in in-game play mode with adequate prizes.
For example from my Magic The Gathering Arena experience, I played many drafts using 3rd party site to just get fun with a special draft format that wasn't available at this time in-game. And then we import drafted decks and play challenges vs each other with a Swiss format. It was usually just for fun or practice.
But overall still for the broader audience, we definitely need to have implemented an interesting limited format. Otherwise, the game will have less chance of surviving :(