I vote no. Warriors do not need this buff, it is a significant boost to an already very strong class.
Warriors and doublesheath
All in all I believe warriors should obtain some kind of other skill. Perhaps maybe some kind of secondary warrior lore (not choosing from the same list). If you think about it warriors do not have many command skills. Most used skills of a warrior is dirt and bash. Kick may pose to be useful, but honestly how many warriors do you ever see use kick? Can't trip because mostly everyone is smart enough to fly, especially with all these easily obtainable consumables.
Warriors also get charge (in which I'm so exhausted hearing about mino charge since its so easily avoidable), but charge is only useful for classes in which do not have counter and is only useful once per tick normally (unless looking for the added dmg). Disarm is quite useless because damn near everything is cursed. Anyone that uses a shield uses a cursed one. Off-hand disarm is about the only useful disarm (exception of few chars whom use cursed dual wields).
I'd just like to see more diversity in each class. So boring when your whole fight is based on bash, or whatever else said skill.
Plus, like someone posted earlier that doublesheath would give easier access to vulns. I wasnt even thinking of it along those lines. Was more thinking along defensive and offensive selections. If compared to blademasters they can switch from defensive to offensive from whichever said skill they have. Warriors must switch weapons for this. So for me to switch from my staff I'd have to flee, run, and pull out my talismans and do this, that and the other.
Warriors already have the most attacks per round, the most defenses in melee, and can always hit you with a weapon you don't know (unless you re another warrior). They don't need more skills. Besides, with the cabal choices a warrior has you almost always have something else you can do besides the usual commands, of which there are plenty already.
Warriors are the most versatile class out there. While I agree they need to be more selective and more diverse, I don't agree adding double sheath will fix anything.
If they get double-sheath they would need a gimp because that's a HUGE change to the dirt/disarm tactic. Now you disarm weapon1, you're lagged for 2 rounds while they just unsheath their 2nd set of weapons and go to town? F that.
What if warriors were a selection class?
We could have Fourth Attack, Riposte, Puggil, Off Hand Disarm, and other stuff as selections, . Akin to D&D Warrior Feets.
Ideas for selections.
Iron Will - +(-5) Mental saves.
Fortification - +(-5) MAl Saves.
Quick reflexes - +(-5) Aff Saves.
Atunement with magic +(-2) Spell saves
Luck of Heroes +3 Luck
Critical Strike - when you roll to check if you miss to armor, if you get a natural 20, you get an unbloked attack (bypasses defences).
Internal Strike - When one of your meele attacks Lands, you roll a dice. If natural 20, damage type is changed to INTERNAL 
Eye Slash - When one of your meele attacks lands, you roll a dice. If Natural 20, you get to slash their eyes, blindness for 0 hours.
Weapon expetise - ... as usual
Weapon Mastery - You can use two Weapon expertise's to make a Mastery.
When wielding a weapon with mastery you can make a Eye Slash or Internal strike with a 19.
Sounds interesting? You take some power, you give some power.
sounds kinda weak tbh. then again i don't think i understand what your trying to say.
Double sheath is virtually quick draw. Everyone gets quick draw via a game mechanic, so the option to put something else in the sheath was the only real way to add a quick draw skill. And honnestly, it should be selectable. A simple peasant warrior would not always know how to draw is weapon with alarming speed, a samarai would. A thief must always be prepared for things to get ugly. As for rangers, and warriors its a toss up, will I learn to quick draw, or will I learn to bash skulls and raid arrows down upon them. Ninja's are up for debate.
Thinking about it from the quick draw point of view, I believe I would have limited double sheath to one handed weapons. But thats just me.
It's like you get a Selection ever 5 levels.
This allows you to keep the same Warriors skills, or change the order you get them.
You like Ripost better to fourth attack. You select it earlier than fourth attack.
Or You decide to skip fourth attack and get the Iron will to strengthen your saves against Necromancers.
You think Off Hand Disarms sucks cause everyone uses cursed daggers, so instead of choosing that one, you chose Internal Strike. Now you have an automatic 5% chance to bypass sanctuary/protection with a Meele strike.
This is akin to Fighter class in D&D. Check it here.
A straight foward class that is highly custumized by selections.
Double sheath is virtually quick draw. Everyone gets quick draw via a game mechanic, so the option to put something else in the sheath was the only real way to add a quick draw skill. And honnestly, it should be selectable. A simple peasant warrior would not always know how to draw is weapon with alarming speed, a samarai would. A thief must always be prepared for things to get ugly. As for rangers, and warriors its a toss up, will I learn to quick draw, or will I learn to bash skulls and raid arrows down upon them. Ninja's are up for debate.
Thinking about it from the quick draw point of view, I believe I would have limited double sheath to one handed weapons. But thats just me.
these are the greatest warriors in the world, simple peasant warrior?
and mya being able to pick the order in which u get stuff doesnt make it customizable, ur all the same class in the end with all the same stuff, see crusaders for an example of customization. The end result should be different in order to be "custom"