Psion said:
The former is admitedly a stickler, but no worse than "why the heck is a halfling longspear as long as a human one". (Just like the halfling longspear, the conclusion per the rules is not difficult, the answer just isn't satisfying.
Actually, it's quite a bit more problematic than that, because it has game balance implications.
The latter seems trivial to me.
It's not trivial. That's the problem.
We know from the PHB that halfling rogues get proficiency in human-sized weapons, not those appropriate to their size. Should then an ogre rogue only have proficiency in human-sized weapons? What balderdash!
So, obviously a race doesn't actually care about the size of the weapon under 3E rules (except for how many hands it takes to hold it). An "ogre-sized" shortsword may actually look like a longsword to a human, but it has to be called an "ogre-sized" shortsword or else the ogre rogue couldn't wield it without the non-proficiency penalty! (Well, actually it's called a Medium Shortsword, but whatever).
This then opens up the possibility of a human wizard wielding a Medium Dagger - he's got proficiency in it (because relative size doesn't matter, per the ogre and halfling), and so effectively can wield a Longsword! Yay!
Obviously, as written, the 3E rules don't work for Large creatures wielding weapons. What then are the design alternatives? Well one way (and you can find these rules in the DMG) is to provide lists of weapon equivalencies.
Thus, an Ogre Rogue, instead of having proficiency in "shortsword", gains proficiency in "longsword". This is a real pain to look up, of course, and the weapon lists in the PH must greatly expand for every possible size of weapon - and new names must be created for them.
Is this simpler than the way it works in 3.5E? I don't think so. Well, it might be simpler, but fills the books with many, many lists. If a new weapon is introduced (Orc Doubleaxe), you must provide about 7 versions of that weapon, each with a distinct name, and conversion tables besides!
I think the problem with the 3.5E weapon size rules is that they
are simple, and thus give verisimilitude problems, like your halfling wielding a human dagger. (That's why in such situations I turn to the optional rules in the DMG and say "it's a small shortsword for you, Mr Halfling!")
Do I think the 3.5E Weapon Size rules are perfect? No, of course not. There are lots of rough spots and places which the rules don't cover. (Stupid lack of missile weapon rules!)
However, at least the rules deal with characters who aren't small or medium in a consistent manner. I think they can be improved more, and I hope they will be.
3E is simpler for most campaigns because it doesn't deal with large or huge creatures.
Cheers!