Lots of people believe in first turn superiority as the reason for most wins. And there have been discussions on having spells cast at the same time, having spells go in order of pips needed to cast the spell. Probably the best way to deal with this would have it focus more on the speed of the player in casting a spell. If it takes me 8 seconds to make a selection while it takes my opponent 4 seconds. They should go first, no turn order. In second round, If it takes me 5 seconds and takes them 9 seconds. I go first.
It's probably the fairest way to deal with it. With all the ways bosses cheat and go twice in one turn, with spell talents that interrupt turn order to cast stuff like spritely, I can't see any way how this couldn't be a possible feature for Player vs Player.
If anyone thinks that this will hurt those with slower computers or with bad connections, remember they are already hurt regardless, by virtue of having a poor connection. How many of you been in the arena where your opponent was inactive for 60 seconds or more?
I thought that some spells would be affected negatively from this, but it wouldn't be. This isn't a drastic change in combat, just a way to solve constant first turn rule. With this, it's all up to the player, there can be no more, "you won because you went first" excuses.