This will be a very unpopular idea!
I think extra turn as a concept should be removed from the game.
After more than two years in the game as I see most fights are about how you can loop. The goal of any strategy and team building is to find a way to loop and not about finding ways to beat the enemy. The enemy doesn’t matter just how you can start to loop.
With removing I mean, remove it from troops, both ability or traits, from weapons, and remove the extra turn on 4 or 5 matches. The only game mode where extra turn should remain is treasure hunt.
Goblins would need a new ability instead of extra turn, weapon nerfs have been requested already.
With this modification I think new and more versatile strategies would emerge, instead of the ultimate “I loop them to death” strategy.