Thank you for the giveaway.
I think it would be fun if there was a tag team feature. It's like placing a card collection that includes a tag team bonus into a battle deck. For example, the Giant Roc card, Flame Imp, and Spark Pixie. If placed in a lineup, it has a tag team + blast bonus.
If one of them dies, the tag team bonus will be lost.

Effects
Side of the battle will increase the probability of an unexpected victory.
On the collection side, players will try to complete their collection to get a tag team bonus. Cards that have low abilities, which have not been in demand, will be hunted by tag team collectors.
Splinterland may publish a list of monsters that have tag team abilities. maybe based on stories, similarities in abilities, or similarities in numbers. a minimum of 3 cards to have a bonus tag.