i think you guys are complelty overlooking the fact that the chinese invented gunpowder in 1000 AD, so in my opinion its possible to have explosives depending on how advanded your city is. i think that this a is good idea, also if you think a sabatour/spy cant carry around 200lbs of gunpowder and sneak past enemy patrols your wrong!!!
Except linear time progression is not certain in alternative worlds. What's discovered after 1000 years in world may not correspond to the other. Also, you're assuming that elements and compounds found here can be found in DoF, and in its relative abundance.