D&D 3.5e isn't historically representative.
If you look at the picture of the swords in the Player's Handbook, you will find that the longsword is actually a picture of a bastard sword, the bastard sword is actually a picture of a longsword and the greatsword is actually a zweihander. There were no "greatswords" per se, it was just a generalization for D&D to classify big long heavy sword that requires two hands.
The bastard sword, or hand and a half sword, had a standard grip for one hand, but also tapered at the bottom with a hefty pommel that could be gripped by the second hand. If you look, once again at the Player's Handbook, that is the photo used by the longsword.
The longsword, historically, was not a one handed blade. The handle grip was designed for two hands. It was a lot lighter and more mobile than the two-handed sword.
When it comes to one handed swords, once again it is a generalization. The Anglo-Saxon Seax wasn't primarily a stabbing (piercing weapon). It was an edged weapon (slashing) and it has been noted as such due to the lack of handguard. Handguards, not only helped protect the fingers from another attack, but also prevented your hand from sliding up the blade when stabbing.
Look at this "short sword" (seax) from Owen Bush. There is very little to stop your hand from sliding off the grip if a stab is made. That would make stabbing with it less likely. Could you stab? Sure, why not. Is it optimal? No.
Look at this "short sword" (gladius) from Cult of Athena. There is a very pronounced handguard to prevent your hand from sliding forward. Also look at the very prominent piercing tip. That would make slicing with it less likely. Could you slice? Sure, why not. Is it optimal? No.
Reading the short swords description in the Player's Handbook will reveal that it is often used as an off-hand weapon. Due to the piercing nature and the european influence of D&D, the short sword in the player's handbook is most likely modeled after a main gauche.
Look at this main gauche from True Swords. It is a little longer than the typical dagger, with a very very deliberate pointed tip. Main gauches, in historical fencing, were designed to parry and stab in conjunction with a rapier, foil, epee, etc.
The wakizashi, in Oriental Adventures, is listed as having the same characteristics as a masterwork short sword. However, wakizashis were made along with and with similar techniques as the katana. One doesn't need to go far to see the cutting tests with the katana.
Look at this wakizashi from Casiberia. The wakizashi has the slight bend to the blade, emphasizing a cutting edge, rather than a piercing tip. Can you pierce with a wakizashi? Of course. Will it slice better? Absolutely.
Use Houserules for alternatives.
Wanting a thrusting short sword? Style it as a gladius. Want a slashing shortsword? Style it as a seax. Your culture and region of play in-game will determine what weapons are available, in use, and how they are used.
The biggest reason I can think of is that Dex, along with Wisdom, is already at least on the border of being "too versatile," in the context of 3.5 and Pathfinder. While it's true that Rogue, for example, is a weak class in the core rules, it isn't due to the reliance on Dexterity.
In 3.5e and PF, Dexterity does these things:
- Determines your initiative. This ensures that Dexterity is at least marginally useful for every class in the entire game.
- Adds to your armor class, and more importantly, boosts your touch AC. Also good for everyone.
- Determines your to-hit with ranged weapons and finesse weapons.
- Determines your reflex save -- another one that's a little important for everyone, since the most common thing that invokes a reflex save is either a trap or an AoE attack, which everyone in the game is likely to be subject to at some point.
- Is the modifying attribute for a proportionally large number of skills relative to other attributes
This is also pretty much identical to the way that 5e handles Dexterity. So why does it work in 5e and not 3.5e and PF? There are some key differences:
- In 5e, touch AC is not a thing. This is important.
- Armor now has a strength requirement on it as you go heavier, as well as being much stricter about limiting Dex bonus to AC, meaning it's either impractical or pointless for most characters to stack a high Dex modifier with something like mithral full plate; heavy armors with improved Dex-to-AC bonuses.
- In 5e, modifiers aren't really a thing outside of your regular old Str/Dex + Proficiency bonus to attack. Magic items are also supposed to be harder to come by, although that can vary with your GM. Depending on whether you can get advantage or not, this might make it harder for you to accumulate the modifiers you want (advantage is supposed to be equivalent to about a +4 or +5 bonus, if I recall correctly)
In conclusion, it's clear that giving Dex the same functions as 5e would make it more powerful in the context of the rest of the rules in PF. I can't say for sure that it would break your game, since that mostly depends on what class the character in question ends up being. Balance in PF depends highly on the individual class.
Best Answer
I’m going to answer “how do I combine Dervish with Lightning Maces,” rather than specifically how to get a slashing mace.
Aptitude Special Ability
The aptitude special ability from Tome of Battle can be applied to a weapon to cause feats that are specifically for another weapon to apply to the weapon with aptitude. It is likely that the designers meant just to let you switch Weapon Focus (dagger) to your aptitude longsword and similar, but the wording of the feat allows even feats where you never had a choice about the weapon type to apply to the aptitude weapon. This is frequently quite powerful, and occasionally completely nonsensical.
If you really want to use maces specifically, you could have an aptitude light mace, and then apply the Versatile Unarmed Strike feat to it. This is probably going to fall into the latter category for most groups, but it’s RAW-legal.
Alternatively, you could use an aptitude slashing weapon, ideally one with a large threat range (the kukri is almost certainly your best bet here: light slashing weapon with a large threat range), and then let Lightning Maces apply to it.
In either case, the Roundabout Kick feat works similarly to Lightning Maces, but for unarmed strikes: once again, aptitude can allow you to take the extra attack with your mace or kukri.
Combined with Disciple of Dispater, the kukris are looking at enormous threat ranges, which means you’ll score a critical on very-nearly every single attack that successfully hits. The maces are only somewhat smaller. Combined with Lightning Maces and Roundabout Kick, every critical triggers two attacks. Your number of attacks is thus more likely to increase rather than decrease; if you hit on the first two or three, you are statistically unlikely to stop attacking until the target is dead.
This is, of course, broken.
Were I your DM, I would allow you to have your slashing mace or allow Dervish to use non-slashing weapons without a second thought. On the other hand, Lightning Maces already is on my banlist. I also consider any combination of aptitude with a feat that couldn’t normally select the weapon in question to be something to be adjudicated by me, on a case-by-case basis.