I think this is new to his latest update. When you stun someone, they get switched to the back. That doesn’t make sense. I stunned that person because she is a major threat, and I want to take her out immediately!
Now, I stun someone, and it switches her out, and then I’m attacking some other weak dude I didn’t want to attack. So I gotta remember every time to switch it back to the stunned person. It’s a pain.
It’s amazing how many times they’ve implemented shitty gameplay tweaks like this, thinking it’s a great idea that couldn’t possible have a downside, when nothing could be further from the truth.
Pure speculation, but I’d expect a character on the way who stuns based on specific matches once a skill is triggered (e.g. a countdown tile is placed and while it’s active any blue match stuns the opponent). This switch-out would make sure you don’t lose out on multiple stuns on a single turn from cascade matches.
My speculation is way simpler than that. I think they put in this change because this is the way THEY play, so they assume everyone else does too; ie, they stun a guy and think, “ok, I don’t need to worry about him for now, let me go attack someone who’s still active”.