Here is my reasoning for the votes that I made.
For part of the reason why I chose palisade as the tool of choice, one of the main reasons was the words of the QM himself earlier:
Defending would've given you Stone-Skinned. The biggest thing that it did for you would be increasing the effectiveness of defensive works and unlocking a few different defense megaprojects; even a Wonder if you proceeded down the path far enough. The downside of the trait line would be that it requires elevated defensive commitments.
Considering how we might be embroiled in a war soon, and with retaliation likely on the horizon now that the Hundred Band's Big Man survived, I think we should try to gain the Stone-Skinned Value at this juncture while we still can. As this recent excerpt has just shown us, palisades make a very big difference in how defensible settlements are. With our current knowledge of settlements alongside our new brick technology, we should be able to construct an improved palisade that should stymie any of their future efforts to retaliate. An improved palisade is not going to be the end all be all solution to this war with the hundred bands. However, it should serve as a good enough stop gap, a speed bump in essence, that will allow us to pursue other avenues in the mean time.
If we can create a palisade that is not only made of brick, but also one that we can have for our archers to stand on we should be able to effectively use our ranged advantage in these settlement battles to gain a decisive advantage. Consider the fact that with the our recent discovery of rice and our dependence on the river system we will likely be more oriented on settlements from now on. Being able to fight better defensively and drain the enemy's raids against us will serve as a key advantage for us. The fact that this choice could possibly give us the chance to unlock defensive megaprojects and a wonder makes it even more enticing to me.
However the greatest advantage it gives to us, is that it allows us more time to work on other options. If we use this lesson to improve our defenses and build an improved palisade we will also gain the ability to work on other avenues of approach while we are safer. For instance, while I agree that we should in principle coalition build, I am not so sure we will be able to successfully do so, enough to convince another tribe to join our coalition, in a timely enough manner. We are asking another tribe who we've just met only a little while ago to fight against a large and powerful opponent, who likely has no vendetta against them, that is a hard bargain for any friend or ally ,let alone one we've just met. We don't want this to turn into another Peace Seeker's moment. As was said before, raiding is not an energy positive activity, and to ask another tribe to commit their warriors and hunters to our fight will likely be a hard struggle. Seeing as we don't have any hero units at the moment that could help us with this task at the moment, that means that it will take time for us to warm up relations enough to gain the trust and friendship of the Arrow Lake Tribe, enough for them to fight with us. To do so however, we will need better defenses than before. In our retaliation we could not kill all of the raiders from the last successful raid on the Fingers, with that Big Man still around they will likely know how to circumvent our defenses again if we do not improve them. In the short term by improving our palisade we will be able to weather a potential retaliatory strike by the Hundred Bands once again, enough so that reinforcements could mop them up, and then use that time gained to pursue other options. That is why I think we should build the palisade.
As for using the prisoners as temporary labor and as a potential avenue for exchange, I think that this war with the Hundred Bands is going to be a long one. If we face their united efforts then they will likely be able to use their larger population to win through attrition. In raiding warfare such as this, it is our most skilled hunters and warriors who will benefit us the most. By trading away non-combatants in exchange for our captured hunters will be able to keep a measure of our strength in order to use it again in the future. Furthermore if we make this into a war of annihilation then that is what we are going to get in the future. Next time there may not be any hostages to save.
Finally, on a more pragmatic note I think not killing the prisoners would be a more honorable decision which would give us more chances to gain another trait or value that will upgrade our civilization in that purview.
That's just my two cents on this vote.