Eh. I have a physique that's pretty similar to an elf's (albeit on the top end of their range). I look pretty scrawny, especially compared to most of the guys I work with. When we do combatives, I throw around guys who outweigh me by a good fifty pounds with brute force alone (God knows it ain't technique). Bulk and strength don't necessarily equate. This reflects in the elf's distinct lack of a Strength penalty. I have to work harder for endurance than I do for burst strength, and I'm easier to break than a bigger Joe is - which is in line with the Constitution penalty. I'm a clumsy stumbleduck, though, so at least there's that break. Thus, it seems rather fishy for you to be saying that because elves are skinny, they can't use a longbow.