I'm not sure how you could do that, in this context. Either you make daiklaves balanced with mundane weapons, at which point it's questionable why they exist, or not taking one for the sake of concept will be a deliberate weakness. There isn't much space in-between.
Okay so, you yourself said that artifacts are equalizers, but you're still approaching the point of artifacts as though they exist to be nothing more than an instantly-applied damage bonus to everything, when that's not how one balances an "equalizing" bonus.
Since the thread keeps bringing up Berserk and Guts, lets actually take a look at how the show itself used and portrayed Guts' skill with fucking enormous swords. (Content warning for general blood and violent mayhem, but well, its
Berserk, so you know what you're getting into)
So here we see Guts using what is arguably an extremely huge mundane sword to mow down dudes (extras) by the handful. This is pre-Dragonslayer, so he's just using a large metal wedge and might, nothing more. This is why when Samson comes into things, he's suddenly in trouble, because this is a heavily-armed and armored, peer-level opponent.
Guts cannot immediately trivialize this guy with a weapon that big, he can only use the sheer hugeness of his sword to prevent himself or Casca from becoming instant-paste against his attacks, and doing so puts him on an entrenched defensive stance. But when he DOES press the attack, he uses that same weight to smash Samson's flail, disarming him and leaving him open to a deathblow. He then goes back to killing piles and piles and piles of enemy soldiers, as one of them even says, "a man dies every time he swings his sword." Not long after he takes an arrow to his hand, keeping him from two-handing, and this is treated as a significant downgrade, suddenly mook-enemies are no longer so trivial.
So what can we draw out of this mechanically? The reach of the weapon matters as much as the power it hits with, and Guts cleaves his way through enemies below his stature by making great sweeping blows which are more useful against multiple enemies than one-on-one. The damage is enough to kill with a single blow, yes, but these are also bumbling mooks, so the damage doesn't have to be Incredible. Samson is another issue entirely, because now blocking equally potent attacks (we see the deflected shot Also instant-kill a bystanding soldier) is Guts' top priority until he can leverage the offensive again, which requires insuring his enemy cannot block and receives the Maximum amount of damage he can inflict with the blow. The arrow-shot preventing him from using both hands shifts the battle out of his favor, so wielding it one-handed is obviously not-ideal, despite his strength.
A huge weighty weapon then could be modeled as a shortish AOE attack, which applies to several bunched-up enemies at once, much like Great Cleave and similar feats, but is fundamentally worthless against single peers. It could give stronger defense against attacks of its own strength, such as not-shattering under the weight of such blows (we've seen inklings of this before in 2e Heavenly Guardian Defense, where mundane weapons shatter against 25 raw damage or higher). Lastly, it could shatter weapons just as strong as itself when used offensively. All of these things are selective and entirely negligible bonuses in the right contexts, primary that of "am I fighting someone as scary as I am or not" and by all accounts can get 'switched off' the moment he can't put both arms behind the strike.
But lets go beyond just human-level enemies, let check out Guts' first battle with Nosferatu Zodd, the Immortal, the most supernatural creature he had ever seen by that point:
Now we see here that his equalizing blade is Not quite so equalizing anymore! In fact, Guts is waaaay out of his league, falling back on that defensive stance simply to survive this time, not just to be protective. Zodd tosses him around like a ragdoll despite his best efforts, and even when Guts gets the option to press the attack, and its clear that this simply huge mundane sword
cannot do the job, no matter how many men it can kill with one stroke. Though he breaks Zodd's weapon as he did against Samson, the deathblow doesn't take, and Guts is now suddenly at the mercy of close combat with an angry and
transforming Apostle. Things understandably get worse from there.
Clearly, mechanically-speaking, at a certain level of opponent the ridiculous damage of Guts' sword doesn't match up. This might be Soak, it might be Health Levels or Hardness, but in any case, Zodd is not someone who can or will go down in a single hit from Anything. Arguably this comes down to enemy/encounter design rather than base weapon stats, but we can easily see Guts using the same tactics as before, and though they
work successfully, this isn't the kind of challenge he can brute-force through on high bonuses alone.
Would these fights be different with the Dragonslayer? Maybe, but maybe not. The only thing the Dragonslayer has over Guts' mundane blade is more size and construction-strength, as sword can only be
so sharp. Would that additional weight be enough added damage to one-shot Zodd? Not very likely, and Zodd's status as a single, outlandishly-powerful opponent rules out most benefits we can tease out from just using a large weapon itself.
No, Guts is going to need a lot more than that, and arguably this would be the domain where Exalted starts providing Charms and offensive magic to help even the scales against beasts of Zodd's caliber.