Critical Hits & Special Manuevers : Too Much

I think something else became clearer in the play-test fight I reported as Blood on the Sand.  This is that Critical Hits and Special Maneuvers kind of overlap too much.  Several times in that fight, I had to stop and think too much about what to do when I got a roll that was both box-cars and 15+.  And that turns out to be a pretty common occurence.  So I think I need to combine those two things.   But which "trigger" to use: box-cars or a Combat Roll of 15+?

I've been debating this for a while now, but I've settled on box-cars being the trigger for a Critical Hit?  Why?  Well, getting a high roll already has an advantage built-in by the One-Roll mechanic.  Plus, I guess I'm just too brainwashed by my past, but I feel like rolling a natural "12" just ought to mean something special.  So, here's the new version:

Combat Results

During each of the three Combat Phases (Melee, Missile, and Sorcery), everyone making an attack of that type makes a Combat Roll with varying results:

Roll is snake-eyes: Fumble
Roll is 10- : Miss
Roll is 11+ : Hit
Roll is box-cars: Critical Hit 

Fumble

If the attacker is using a weapon made of natural, non-metallic materials, it breaks.   The Referee should feel free to apply other results; for example, he may rule that Artifacts also break on a fumble or perhaps just run out of power.

Miss

Um...miss.

Hit

The degree of success indicates base damage done. This is modified by the weapon’s Damage Multiplier.

Critical Hit

A roll of box-cars results in one of two effects: Automatic Hit or Special Maneuver.

Automatic Hit - if the attacker had no chance to roll 11+ due to modifiers (from Weapon vs. AC, opponent's Defense, etc.) , he still hits on box-cars.  This hit counts as a Combat Roll as 12 i.e. the degree of success is 2.   This means that everyone has at least some chance of hitting any foe.

If the attacker has no need for an automatic hit, then he can choose a Special Maneuver:

Break Natural Armour/Shield - if the foe’s armour and/or shield if made of natural materials, it breaks and becomes useless.   If both armour and shield are susceptible to this effect, the shield will always break first.

Extra Damage - the weapon’s Damage Multiplier increases by one. A Tiny Weapon goes from x ½ to x1, a Small Weapon goes from x1 to x2, and so on.

Wound - the opponent must roll on the Wounds Table (which usually happens only if reduced to 0 or less HP).  This Wound is always temporary.

Knock Down/Back - the foe stumbles back a few feet or falls down.  He needs to use a Half-Move to stand up or lose all Defense.

Disarm - the foe’s weapon goes flying out of his hand.  He must use a Half-Move to draw another weapon.

Stunning Flurry - a flurry of disorienting blows that forces the foe to make an INT Throw or lose his next turn.

Deadly Display - the character's display of martial prowess is so intimidating that the foe must immediately make a Morale Throw.  This is only useful against NPC's as player characters never make Morale Throws.

The Referee should feel free to add any other Special Maneuvers that seem fun.