10 in STR, 1 in DEX vs 10 in DEX, 1 in STR

David VS Goliath scenario much? :3

human have foreheads, we can win!

Not really applicable.

The big issue in D v G is that David was a _shepherd_ and knew essentially nothing about combat, and therefore brought a "non dueling" weapon to a duel. The Philistines (aka Phoenicians) knew perfectly well about slings - that just wasn't the point of the personal challenge... moving on.

In this case, Kitter is being trained by the house arms master with a smallsword (even a rapier would be too heavy for a yinglet). His goal is to keep moving and then stab you and he's not going to try to parry beyond glancing deflections.

As to the choice of weapon... well... I highly doubt Shadiversity's "Best weapons for" series would pick smallsword for a yinglet (aside: Shad seems to hate the thing anyawy). My bet would be spear/polearm remaining as the top choice for a yinglet (as is canon for them) because of the reach advantage and the fact that it doesn't take as much in the way of lower arm strength. But this is an upper-class family and they're not really training Kitter for the battlefield.

But amusingly, to come full circle: a sling, or better, a staff-sling, would be a good choice for a yinglet as it depends much less on strength than many weapons do, and more on coordination.

Oooooh, stave-slings. :D

Eh... D&D's stats are one of my least favorite things of a system I generally prefer - lumping agility, coordination, and dexterity all together in one "DEX" is more oversimplification than I care for.

The arms master is on the good end of normal strength, so probably more in the 11-12 range. A yinglet would probably be in the general area of 3.

His dexterity is good - probably 13, but even a derp yinglet is faster than a human and Kitter is actually quite a good specimen, more like 16: he can move that smallsword around like a child with a willow switch. He's not going for a big hit: he's going for a quick stab. Enough of those (or a lucky one in the right place) and the human's strength just isn't going to help. But fast as he is, Kitter's low strength mean he's not parrying a thing: his dex bonus to armor class is nonexistent.

It's agility where the human is at a huge disadvantage: more mass = more interia. Arms master is good, a solid 10, but yinglets EXCEL at that and Kitter's natural 18 means he can quite literally run rings around his teacher... if he remembers to move instead of standing with his feet rooted to the ground. His agility means that the human is going to have a hard time ever landing a hit, or getting near enough to _need_ to be parried: Kitter gets a HUGE effective armor class bonus.

Coordination sees Kitter at a disadvantage, but that's because coordination is as much training and practice as any natural talent. The long years of experience of the arms master see his at 16, while poor beginner Kitter stands at 8.