Look, if this isn't a hard thing to get right then why are you so determined to get it wrong?
Slings do not hit as hard as crossbows and no one ever said they did. But if how hard you hit is what you see as important then you just need two slings to match a crossbow. Saying "they don't hit hard enough" when crossbows can do the job is fundamentally not an issue if you are enabling more people to fight.
To match two crossbows, you'd need 4 slings. Yes, I get the idea that "every single halfling will have a sling and can fight" but relying ONLY on slings is the issue at hand here. At a certain point, the numbers are just too ridiculous.
The range is a point but not an overwhelming one. You are talking about "have to be within 30ft". Why? Again this is an issue of numbers. They have to be within 120ft, sure. Or take cover. Again, you need more halflings.
120 ft, in the dark? Remember I said the gnolls would attack at night when they have the advantage. And this tanks the halflings accuracy. Dropping them to 25%. Meanwhile, the gnolls are sitting at 44% I believe I said. And so, now you need 4 halflings with slings to cover two crossbows, and then 8 halflings to guarantee two hits.
But gnolls need 6 hits to be taken out, so now to take out a single gnoll the numbers are looking at 48 halflings to take out a single gnoll.
Yeah, this IS an issue of numbers. And range, and cover. Because all this cover the halflings are using can benefit the gnolls too. Not for 3/4, but for 1/2 cover. So, the gnolls could end up with +2 AC, dropping the halfling accuracy even more. And since the Gnolls can attack from much further than the halflings, they can do exactly what it says they do in the book, soften up the target from range before moving in. They fire from 200 ft out, far beyond what the halflings can take, while a second group moves into melee.
This isn't even difficult tactics. And it ruins your proposed situations.
But the point of the sling is that every halfling can carry one at all times. It's about 1lb of weight including the stones and you wear it on your belt or in your pockets.
This doesn't mysteriously prevent halflings who think they will need them from wearing shortbows (or, more rarely, light crossbows) on their back. And if they happen to be home when there's a call to deal with invaders then any who have and can use bows will grab them - and possibly those of other people in the house too to bring them.
Right. This, this right here? This is my point. They can have better weapons and use them. IF you want to make it 5 crossbows, 10 shortbows and 30 slingers, fine whatever, my point has only been that just having slingers isn't enough.
But the point of the slings is that pretty close to 100% of teenage and adult halflings are ready to defend their community at almost no notice and can and will make a meaningful contribution.
By contrast humans are much more likely to use a formal militia system with designated people on designated days carrying the effective weapons. Wandering round with 6lb of bulky crossbow + bolts on their backs and possibly armour that gets in the way of what they are intending to do that day.
Yes, humans take a different approach. So what? The human approach also includes walls and tends to work pretty well actually. Not perfectly, because gnolls still raid and destroy human villages, but it works as well as any strategy can.
Only people doing better are elves and dwarves, who with universal weapon training and severe terrain advantages are nearly impregnable.
The gnolls are only partially relevant. The big question is which system is better for protecting the village from a range of threats? The one with the designated militia? Or the one by the race noted for its farming where everyone is able to contribute to the defence at a moment's notice even if a slinger only provides about a third of the firepower that a properly equipped militia member does.
If humans can protect a village with a militia then halflings can primarily with slings. And if somewhere would be untenable for halflings then it is for humans.
If, on the other hand the place is so dangerous that all the humans are wearing crossbows or military weapons like polearms at all times then yes, slings aren't enough. But this is a weird village.
I know you are committed to this idea that the moment a threat enters the village, 60 halflings drop everything they are doing, pull their slings, and crack sixty stones at the threat, all within 10 seconds, but the entire point I'm trying to make is that there is no reason not to have better weapons in the village, and people who are expected and trained to use them.
Because there is a counter-point here. If you didn't need those men in armor and better weapons, if every single threat could be taken out by people with a strip of leather and a handful of rocks... why would better weapons and armor even exist? Why would humans pay all that money they covet to have all this armor and weaponry when they don't need it?
Sling is 1d4+2, average of 1d4 is 2.5, 2.5+2= 4.5. turning 4.5 into a range is 4 to 5. True average of two shots is 9
Light crossbow is 1d8+2, average of 1d8 is 4.5, 4.5+2 = 6.5. Turning 6.5 into a range is 6 to 7. True average of two shots is 13
I guess you take exception to me saying "double the damage" when technically two slings is 1.3846 times the damage of a crossbow? I mean, it takes two, which is double of one, and you really can't do 0.40 of an attack.
Well, I guess when you start taking into account range, accuracy, ect, which the light crossbow has better range the ability to not be at disadvantage. At a range of 50 ft the sling is approximately 25% accuracy, which I think takes the average damage of 9 from two shots to closer to 2.25, while the crossbow would be closer to 40% accuracy, taking that single of 6 to 2.4, which is about the same... one crossbow to two slings. Double the number of slings.
Have I satisfactorily over explained what I simplified before?