Something I just realized that we have all been overlooking. Combat takes place simultaneously. The results of the combat are just resolved according to the initiative order.
I always cringe just slightly when this topic comes up. Probably why I like either a very specific, second by second, system or a more broad, all encompassing, round (the BattleTech round). I've never understood why I'd bother with everyone rolling initiative if it really didn't impact the final outcome of the round.
I'll try to give an example of my idea of how a 'longer' round (10 second to 1 minute) goes without being long winded...
My opinion is that
movement in a round is very fluid or abstract. Two combatants are constantly moving to some degree, repositioning, feinting attacks, looking for openings, changing their stance, checking their surroundings, etc. But the attack roll itself is 'the' opening that they feel they have the best shot of landing a blow and is, therefore, the one they roll for. The greater the skill the more opportunities they may (feel they) have - i.e. multiple attacks. Therefore, while two miniatures may be sitting still in two hexes facing each other, in reality they are bobbing and weaving and so forth (implied movement).
As a small example, Rolemaster gives a third attacker a bonus. If you are fighting two foes you are most likely going to put them on your right and left forward flanks. Therefore if a character is standing looking East, and two foes approach from the West, I'm going to allow the character to turn and face them for free. When faced with three opponents the player is going to need to chose if his character is directly facing one foe, giving the two others rear flank attacks, or facing two foes (right and left forward flanks) and giving one foe a direct back attack advantage. (We're assuming an open battlefield, if there were walls or obstacles each side could use them to their advantage obviously).
However, from there, the
initiative determines who gets that first jab in. Which of the two sees their first opening. When a ranged attacker sees a good 'lane' open up to their target. Etc.
In this way you slightly abstract movement, but not attack actions. This does away with the idea that the damage you do is 'a series of blows' since that doesn't jive very well with how Rolemaster attack and critical tables work. But allows for the explanation of a lot of other things that might happen over the course of the round.
This way initiative really means something.
Imagine two of your friends fighting and getting into a scrap and you decide you're going to shoot into the combat as they are squirming and moving around. The reality is that you wouldn't throw a rock into a melee scuffle to help a friend out in combat.
I'm with jdale on this. Simulate it as a penalty to keep it simple.
Allow the player their roll, just make it less likely to hit. Keep the same, basic, balance, but let the player to continue to feel more engaged.