... since the quantity of all of your requested trade goods (which is only a possibility with the dwarven caravan anyway) is capped at 4 ...
Either you're misunderstanding something here, or I am. The slider set in the diplomatic meetings is not "quantity". I believe it's more akin to the urgency you require said goods, such that there is likely to be more of the caravan's weigh limit devoted to bringing you numbers of that particular item.
I really don't blame you for that analysis, as that was once my interpretation as well--and I really, really wish I'd been right. Because that's the way the game
should stock the caravan sent to your fort: 50% is items that you actually
asked for, 20% is raw goods that the Mountainhome assumes you might need (always including the "basic necessities" of 1 anvil, pick, & axe), and 30% is random trade goods that the Mountainhome wants to slough off to the ingrates living in the border towns. So, if the only item that your noble asked the trade liaison for was raw marble, you
shouldn't get just 4 lumps of marble (5, if you're lucky) at double the regular price, you should get "as much marble as we felt like shipping to you, given the various factors affecting our supply & your indicated demand" at a cost markup of "however much we decided we could charge you & still sell most of our load".
Part of the problem . . . is that the carry capacity of the animals (and wagons) is absurd. My games are modded with them being about 10-20% of current values (I'm still fussing with it to find a happy medium).
Scroll down just a bit on
this wiki page to see an image that sums up the situation perfectly, and know that I wholeheartedly agree with you.
Wagons still drop 'wagon wood'? Thats why I like them. They drop wagon wood and I can memorialize them.
Um . . . okay. Unless you have a noble who's actually
good for something, in spite of their preference for wagon wood, I'm not sure why you would wish to
hurt your trade relations, but hey, whatever. Goblin-pushed siege towers and hand-pumped fire engines (that spray water, not fire) do indeed sound cool, though frankly, I see more immediate applications of the "wagon-creature" model for more actual
creature-type creatures. Bronze colossi have been able to fit into 1-tile-wide, 1 z-level hallways for FAR too long. Also, high five.
I'm pretty sure I remember a caravan bringing wagons with about a dozen hematite on request when I was in an ironless embark.The wiki page you linked doesn't say anything about this cap of 4, either. Are you sure? Maybe they've only been bringing you four because they hit the weight limit without their wagons.
I'm not
absolutely sure, but I'm sure enough to say that I think that instead of 12 hematite, the caravan probably brought you 4 hematite, 4 magnetite, & 4 limonite. I know I've mentioned the "Rule of 4" on the forums before, and been backed up by some who are wise in the ways of drunken lunatics, and I also know that when I've built up trade to ensure a large caravan next year, and place high demand on only a few things, I don't get more of THOSE things, I get more worthless crap like sandy loam, pyrite scepters, and barrels of walrus blood.
I'll compile a list.
REASONS TO USE WAGONS
1) Larger carrying capacity (of debatable benefit)
2) In 0.40+ versions, loadout is much faster (possibly true of pack animals as well), reducing the odds of a noble throwing down an after-the-fact trade restriction
3) Wagons can take paths that other creatures cannot, allowing the player to build routes that put wagons on "safe ground" almost immediately upon arrival
4) Spawn points for wagons can be controlled slightly more easily than those for pack animals
5) "Slain" wagons drop wagon wood (of laughably debatable benefit)
REASONS TO USE PACK ANIMALS
A) Pack animals can traverse 1-tile-wide paths, as well as stairs, doors, and traps
B) In versions prior to 0.40, heavily laden human wagons could get stuck in a "traffic jam" with the incoming dwarf wagons (if you're using only a single Trade Depot, which is highly recommended), resulting in the collapse of both caravans
Personally, I would "weigh" the merits of the two lists as being just about equal, simply because Reason A carries
so much security: Pack animals can enter via a narrow hallway that is absolutely PAVED with traps, and if anything extremely nasty (and trapavoid) comes in, we can just slam the doors in its face, which will slow it down long enough for use to build walls & seal the entrance completely. With wagons, the only security depends on the circuitous route the wagon must take, and/or the risk of losing a few military dwarves to Lashers & marksgoblins, and in the event of something nasty, praying that somebody will Pull the Lever to raise the drawbridge in time.