Killing the chain of command is really good, but
3 x 100 = 300 and
50000 - 300 = still around 50000. Doesn't seem to make lot of an impact. I read somewhere, an army is deemed to be defeated, when a certain percentage of its soldiers is wiped out. And that number wasn't that high, but surly it wasn't less then 1%. Well, at least it will create chaos with all those commanders out of the picture and if the other army arrives in the meantime, it can deploy.
But burning those rations? IDK. The soldiers on both sides are still soldiers of the kingdom and are needed after the civil war no matter who is victorious. They have to be feed the coming weeks anyways. Those fires surly won't destroy all the stocks and the battle will last for some hours, maybe days, so there will be enough food to keep them fed for the battle, but not enough, when everything is settled and that food must be replaced with the food of the population. Burning it doesn't seem to make much sense.
@BagOfGlass. The funny thing with the butterfly effect is, it's a matter of impact. A small change in the past can make a big difference in unstable systems like the resulting lottery numbers in a lotto draw, which in turn can have a huge effect on certain lifes. But even if years have past, it won't make a big difference in the GDP of a nation. Given several decades on the other hand...
So global whether systems are too big to be influenced by the untimely death of a king or different troop movements behind the scenes of the demon kingdom. At least not in such a short time period of a few years. While the clouds might look different and the rain might set in a few minutes earlier or later, the storm will surly come.