Out of all the weapons in the game the only ones I find a bit off putting are the whip and scourge. A morningstar, for instance, was a weapon designed for wrecking armor and getting hit by one would literally shatter bone and do all sorts of massive soft tissue damage in real life. Weapons with small contact areas such as spears and pikes were similarly made for punching through armor and deep into opponents and I see no issue with them doing so but a whip exploding somebody's head through a steel helmet is just plain silly.
My problem with morning stars is how deeply they penetrate. The effectiveness of their tips will vary, either they are small, don't penetrate deeply, but will more often than not penetrate causing relatively minor damage, or they have large tips that are wide, penetrate less often but further. I also have a problem with the way the game models their hit. Because of the many points, its likely that several points will hit the target at different angles, which will absorb much of the momentum, but right now when they hit, only a single point is taken into account.
My problem with knives is contact area, but we could potentially argue velocity. They pretty much pierce everything (much like the morning star). An iron dagger will, by nature of material and momentum, have a hard time piercing iron armor. Right now they seem to be modeled after ice picks that don't blunt during strikes.
...The game basically treats the supper sonic tip of the whip as having the entire weight of the whip behind it which is why you get exploding heads and such. For those who are trying to "fix" the whips I think rather than increasing its contact area you might want to decrease its size...
Thats a great idea, I'll probably use that too. I'd argue that the contact area is still too small though.
Whips could be used in "combat," but suffer from a few problems. Armor will completely negate any damage. In the context of DF, that means fighting villagers, not heavily armored dwarves. So I could see some goblins using whips quite often, but not when attacking a fortress. Of course, we could argue that goblins are just that stupid?..