I don't think that fights need to be designed with the intention of perfect execution being possible. Let players work their ingenuity and find solutions to the impossible. That's how you get a skill differential.

I really want to know what's the deal with these endless positional discussions involving people who have no investment in the role. I've never seen a thread where players ask for the option to move around while channeling spells. I think magical ranged players have this mindset that if melee lose their positionals, then they can dismiss melee skill expression the same way that they have done for physical ranged. Perhaps it's time that we flipped this around and start focusing on magical ranged gameplay simplifications.