Ideally I'd like there to be a widget that players used to set up their troop and spell buttons for use in combat.
I realize that that is a tall order, but I would be quite satisfied if the spell buttons started from the right.
I did search the discarded ideas and there was something similar requested to prevent miscasts. Reason being: "This would cause more problems then it would solve; all players have to do to solve this problem is to be a bit more careful where they click."
I understand that a revamp of how spells are used is not viable and agree that the way spells are used should be left alone. I do feel like a simple edit to place spell buttons on the right of the bar instead of picking up at the end of the trained/available troops from the left would prevent miscasts and be easy for players to adapt to while at the same time not changing any mechanics that are already in place.