So...
They managed to make a fireweapon that is longer ranged than our fireballs, magic proof, apperently cheaper, seemingly deadlier, stays in place, and all that.
Well, I'll scrap the range, that comes from their ballistae.
I'm going to call upon Rule 2.
2. Keep in mind that I am not a historian, so there will sometimes be mistakes and inaccuracies. Even in the best of circumstances, minor inconsistencies are a common occurrence. If some piece of equipment is imbalanced/unrealistic, I might consider changing it if you bring it up once -AND ONLY ONCE- and politely state your argument. However, I will err on the side of consistency with my own game, I do not like to go back and change things. Sometimes it is more important to simply keep the game running smoothly than other concerns
My argument here is simple.
It is inconsistent for a single design roll to be vastly more powerfull than several design rolls made over a long period of time.
To start: By virtue of being magical, magical fire must be better than normal fire. If it isn't (ie, mundane fireweapons are easier to develop than fireballs), then we got heavily disadvantaged when choosing our starting wand.
I assume Iituem did not intend that, so to be consistent magical fire must be better than normal fire.After all, I would not expect a simple designed peptalk to defeat Moskurg's wand of heroism.
Now, the modifiers we got for our fireball wand were significant. We got -1 for Firewand reverse engineering, and -1 for making it stick for an hour. I emphatize that was with a design bonus.
Secondly, the design is ahistorical. The molotov cocktail was invented in the second world war. That is several centuries further away than our steam engine. Sure, alternative fire things existed in history, but those all relied on rare resources Moskurg should not posses.
Third, it's not consistent with our own rolls. When we designed the Design: Antimagic Bombs [6, 4, 5], which were even based on existing tech, we had serious limitations in range, applicability and damage. It was an explosive arrow that needed repeated fire to pierce shields. It started fires, but only very tiny ones. It had shrapnel, but stopped by armor. Our enemy does not share any of those disadvantages for their fire-stuff. In fact, their fire-stuff is completely immune to means of stopping fire.
Therefore, I do not think the design is consistent with either historical interpretations nor game mechanics as applied before now.