When I click on a troop, I want to see what it does, i.e. its spell. The stats are already directly visible in the collection and the combat screens. Defaulting it to centre panel again would not be a QoL improvement to me. I like it the way it is, but I understand other players have their own preferences.
Why not just show all three panels side-by-side, so spells, stats, and traits are all viewable at once?