I do not see a problem when trying to picture it.
A short sword would be close to a knife for example, but how could your troll wear a small / medium helmet?

Seems like a paint picture challenge to me ;)

@ Orbic:

Largely I agree with you. However I also hold the opinion that sometimes for consistency and ease of understanding some things should be simple and uniform. It's already an unnecessarily complex system to have so many different armor & weapon sizes (and obviously we're not going for pure realism here because there still is a cookie-cutter size-less variety) and I think making the armor and weapon size qualifications vary within a race is just taking a step too far. At least, that was my rationale when reporting as a bug. I don't think I'm completely without point, though, am I? ;)

I actually love the current behaviour. Trolls are so big that they can wield two-handed human weapons with a single hand. I guess the same thing happens with humans vs. gnomes. This is the kind of detail and complexity I love in roguelikes. And wait until we have armour smiths that fit armour to different sizes, or "scrolls of resizing". Lots of possibilities!

@ Al-Khwarizmi
Yeah, alright. For the time being you've convinced me. That and the fact that yet again I was wrong about there being standard, non-sized armors. If all armors have a size than maybe we are going for realism! :D

Really? I noticed the 'Larger can wield smaller' weapons, but not the part about smaller 2H weapons being 1H... that might have some interesting implications regarding artifacts. Imagine dualwielding Vanquisher and TotRR or something like that.

On an another amusing note, my trollish barbarian ended up with a very small (tiny?) rapier... I had the rather amusing image of him using it as a toothpick.

Maybe certain artifact items would shrink or grow to be the appropriate size for their wielder. I imagine magick rings would do something like this but I don't know if Thomas has considered this at all for artifact items

The feature definitely is intentional. This probably will be easier to understand once I start writing the manual (scheduled for the 0.3.x development line) due to the amount of details already creeping into the game.