Basically, this is two suggestions both based around the same topic, stone tools.
Sharpenable Stones
This is quite a simple suggestion. Based on the Dwarves technology, I am assuming that the stone components of the obsidian swords are made using various knapping techniques (knocking chips off the stone until you have the desired shape).
If this is the case, then there are quite a few other stones that should also count as Sharpeneble. For example, flint is even better that Obsidian for taking an edge when knapping, and chert can also be used in a similar way.
Basically, this suggestion is that it should be possible to make stone weapons/tools out of quite a few types of stone, rather than just Obsidian.
Stone Tools
This suggestion is a bit more complex. If we can make stone short swords (which would only be effective if they were small stone flakes mounted on another component) then why can't we make stone axes? Stone axes and blades are very sharp, and it would make sence to include stone axes, since stone swords are already in.
However, if stone tools are more effective than metal tools as well as being easier to obtain, what would be the downside? I propose that the downside would be that every time a stone tools/weapon is used, there is a chance that it will break. Afterall, stone tools/weapons might be sharp, but they are also very brittle.
eg If a dwarf armed with a stone sword attacks a goblin, then the goblin will be armed but it is also possible that the sword will either become blunt (mildly damaged) or break completely. Blunt weapons would have to be dumped, but would at least give the dwarf something to use in the rest of the combat, whereas a broken weapon would be destroyed and disapear, leaving the dwarf unarmed.
eg A dwarf woodcutter has a stone axe, for each tree he cuts down, there is a chance that it will destroy the axe in the process. This would mean that tools and weapons could be produced easily and in great quantity, but would need to be replaced often.
This system would also leave room for a similar wear system to be implemented for metal tools/weapons, but without the possibility of destruction and also with the possibility of repairing the weapon (steel axe gets blunt? re-sharpen it). Various metals could also have different levels of durability, but that is a suggestion for another time.
The main suggestions here are for more stones to be considered sharpenable and for the possibility of stone tools which would be cheap, numerous but also temporary.