I think you should be able to choose your own defenders. Or at least be able to choose what stat has priority when defending. For instance I have a Maxed out Juggernaut and Ironman, but I am trying to level my 2 star storm. Now that she is higher then juggernaut she takes over defending even though she has way less health, which I find more important when I’m being attacked. It picking the highest level just makes it easier for those who have already Maxed out a couple characters to bully the ones trying to level new ones. Sure I’m not the only one who feels this way.
Your highest level characters aren’t picked as your defending team.
Your defending team is the one you last won a match with, or the exact one (including level) you beat the opponent with for retaliations.
Even still it would be nice to be able to pick my own defense
But you can: pick them and win a match, done.
If everyone could pick any random team as their defense team then we’d all just figure out who the best defensive team is at each level of play 1*/2*/3* and put them in.
I for one don’t want to have to fight the exact same team in every single match that oh by the way has been deemed to be the best at defense.