It's a little unrealistic, but it's better than cyclic initiative. In cyclic initiative, if the guard wins initiative, the barbarian can never catch up. That's a problem that this method addresses. It accomplishes my intended goals. Sure there are still corner cases, but simultaneous-ish resolution leaves a lot more room for the DM to adjudicate those.My fundamental issue with the various simultaneous/concurrent/word-of-choice resolution systems is that they still end up with weird corner cases that defy their intended goals....the winner of the contest is allowed to complete their whole declaration, even in events where it makes no sense. To refer to the barbarian vs guard example, if the barbarian wins, he can close 30' and make his attack before the guard can move a step. This harkens straight back to the cyclical initiative problems that this method is meant to address.
But there is a conflict. If the barbarian moves before the guard, the guard's movement will provoke an opportunity attack. The only way to avoid that is to make movement simultaneous. Maybe with an Athletics contest to see who can get there first, but then that's basically the same as rolling initiative.So, suggestion for a correction -- phased initiatives. You would still declare your entire action at the beginning of the round/cycle/word of choice, but it's execution then proceeds in phases. A phase would be a move or action. So, in the barbarian vs guard example, the barbarian declares he will close and attack, the guard declares he will retreat and shoot. The first phase will be the first part of the declaration, in this case, both move. As there's no conflict yet, play continues without a resolution.
Then the second phase occurs, the guard shoots, and the barbarian looks confused. That's not fun, though...
This is where we disagree. The fun comes from not knowing what's going to happen when you declare your action. If the barbarian really wanted to decrease his risk of wasting an action, he should've declared Dash in the first place, or used a ranged attack. "Move and swing" was a strategy with high risk and high reward (win initiative and swing, or lose initiative and whiff). It makes the initiative roll exciting when you don't know what's going to happen. That whole risk/reward thing is lost if players can change their mind after they know what's going on (as in cyclic initiative, as I show in my example). That's the goal of separating declaration and resolution.I'm not a fan of 'guess correctly at the start or you've wasted your actions."
(It's fun for the players when they can make the monsters waste actions. PCs will generally have higher INT than monsters, so this will be to the players' benefit more often than not.)