Vortamic is Possible to Beat
I am obviously new to this site, but not new to Knights and Merchants. I've been playing it since 1999, I believe. I have never played with other people, but I consider myself an expert at beating the computer because I have beat the TPR and K&M missions in more than one way to finally make the game somewhat "boring" and "too simple".
Anyway, I downloaded the remake on 4/26/2013, and I just played Ben's Vortamic the past couple of days. First of all, I have to say that this was the most challenging scenario I had to play. It's radical really, especially the initial attacks..."it separates the boys from the men"! (No offense intended...when I first tried this scenario, I was in the same boat as other experts...it was HARD). In addition, the map is so beautiful, highly detailed, and creative that it can't compare with any of the original maps for K&M and TPR, at least.
Anyway,
Although it might be believed to be impossible to beat, it actually is possible with the current settings Ben left in. I have uploaded my saved game which proves this. Vortamic. I obviously didn't take out the city to the far north yet, but as you can see, it's unquestionable that I could if I wanted to because I've got a strong town and practically own the entire map. With the market available (which I don't particularly like in the game because it makes it too easy...I do confess I used it to make gold for this particular mission since sufficient gold ore isn't reachable...but I'm sure it's possible to not use the market at all even in this scenario).
I didn't record the game, as I have the habit of saving the game repeatedly as I play just in case something unexpected goes wrong or if I make the wrong call in battle (hey, it's single player so it doesn't matter, right?) .
Strategy: Surviving the Initial attacks (and taking out the east town)
Obviously if you're going to defeat a large army and you have a small one,
Assuming you have at least some bowman and/or crossbowman, the optimal location to fight is in one similar to the one Ben provided: only a small gap is opened between two mountains (or rivers, etc.) so that you can force the large army to await being killed.
The problem is, even just keeping all of your soldiers inside of this "circle" which Ben provided, as others have said, there are SO MANY KNIGHTS. What you need to do for this particular mission is have one of your laborers build the fence for a quarry (a 3x2 block) in that gap and have another laborer build a fence of a quarry above that one. You then move your soldiers right next to the single man openings on both sides of the fences to only allow one enemy soldier to "have a swing" in each of those gaps. IMPORTANT: you need to have your archers right behind these fences so that their arrows don't destroy them (if for some reason the fences still get destroyed, retry until they don't...it's possible for them to stay up).
In addition, have two laborers build two barracks fences to your left to execute the same strategy of allowing few soldiers (knights in this case) enter from the left, should they be so anxious to kill you that they are willing to go around the iron ore mountain to get you from the left: have a few knights guarding the gaps between the barracks' fences (split your knight group into two groups).
With about a dozen times of trying this strategy, you should not only be successful in surviving the initial attacks, but you should be able to manage to keep most if not all of your bowmen and crossbowmen, but you should have enough soldiers to go take out the village to east, again, having some of your labors go all the way over there and build fences for maybe a store house or something (if the trees there allow you to place those fences).
After you take out the east village, you should have almost all of your bowmen and crossbowmen, but probably not many infantry/cavalry (I think I just had 1 pikeman and one knight left).
Ben gives you some leather armor and weapons to start with, so, I personally chose to make 9 axe fighters (I had enough bowmen and crossbowmen already). The militia and lance carriers die so easily against iron-armored unites in comparison to axe fighters that I thought it was worth it instead of creating 9 militia and 9 lance carriers. Just my opinion.
Strategy: Surviving the continual annoying attacks from the town immediately to the north
Starting out with such a hardship, you really don't have that much time to build a strong town to have a good food supply (not to mention produce strong soldiers) before you get attacks from the town immediately to the north.
All you need to do is have your laborer's build fences for different buildings around the trees and coal deposits to the north of your town and they will come and attack every minute or so: they take out 1-3 fences in each "attack". Train extra laborers to always have at least 5 fences up before they make another attack, otherwise they will attack a building which is actually built! You should train the extra laborers because you want to build a town at the same time that you're constantly...and I mean constantly...having to rebuild fences of buildings.
For those who have one all 20 missions of K&M or all 14 missions of TPR, the rest is very self explanatory.