After thinking it over Dextrity gets you the hit, Strength does the damage, and Endurance allows you to do it repeatedly. While Strength will make a given weapon easier to hold and manipulate, attacks launched with full strength require a lot of energy and that wears on Endurance. Defense requires less power and so, while it should wear on Endurance somewhat, Strength should mitigate this.
It all sounds vary similar to CT with the exception of Endurance wearing out at a slower rate while parrying and to do that with any real balance would require keeping track of fractional Endurance points and no one would want that.
Add to that that Dexterity also protects against attacks by allowing for faster, more effective parrying and dodging.
The model I like is the one in Runequest - Strength increases damage and gives a bonus for forcing through and opponent's parry or block. Dexterity gives a bonus to speed (and thus order of attacks) and dodging, and Endurance tells you how many rounds you can attack until you start gaining cumulative negative DM's and is modified up or down by how much weight you are carrying, including the weapons and armor.
Anyone can parry and dodge unlimited times and Endurance has no effect on it - you just won't be scoring hits is all (which reminds me of what a master pointed out to me once about how new fencers think they are D'artagnan himself just because they can defend themselves all day against even the best fencer - but the rub is that they still lose because attacking
and defending is what wins bouts)
Blocking (as in with a shield, which is counted as a weapon - not armor) is treated as an attack so Blocks reduce the Endurance (and weight carried modifies)-limited attacks at full strength.
So depending on one's attributes you can pick and choose among the armors, weapons, and their various means of protecting you and hurting others to get a happy medium. As your skills increase there develops a trade-off that simulates real life: if your skill in parrying (or blocking) is high then you can afford to wear less armor and gain a speed and endurance advantage...if your attack increases but you have low Dexterity and poor parrying then you can probably get by with gambling on heavier armor and less rounds to attack at full strength since one or two hits bashing through your opponent's defenses will do the trick.
For example: someone with a high skill in attack with one-handed sword could start using lighter swords combined with less armor to gain more and faster strikes (attacks) each combat before running out of steam. The pay-off would be that he would more likely hit first, more often, and probably still have more full-strength hits left after his heavier opponent was exhausted. The downside would be if he couldn't do enough damage to penetrate his opponent's armor so obviously adjustments are made as the need arises.
Still, this model, designed by people who actually used these weapons in the SCA and competitive fencing, are the most accurate and consistently realistic ones I've come across yet that don't require a laptop for tracking all the stats.