So a problem that I'm continuously met by is having people come to my City and attack it, they're around my power - So I duel and drop a full army... They drop a single Hero and I lose 6 or 7 Energy (collectively), I understand that they lose the same energy and take injuries, but multiple people can do this and sap my energy.
I don't feel that it would be fair to force a defender to meet the same power requirement as if they were attacking - However, I do feel like that they should be forced to drop some degree of troops, maybe half of the power as if they attacked the other person in the duel. If they don't, they lose by default. If neither side meets the power requirement, the attacker loses by default. This would provide a much fairer circumstance, people who are going to go offline for 2+ hours currently provoke a fight and then waste your energy at no real loss to themselves, with my suggested change they would either lose troops or forfeit, thus you wouldn't dicked over by baiters.