Why not? there are 4 barracks, 2 dark barracks, but only one spell factory, it takes forever to make up spells, however if there was more then players would be able to get a better use from their spells without having to wait 2 hours for the next batch to finsh. I would recommend having only 2 though. It would look the same, do the same and be like the barracks where at level 1 you could only make lightning spells etc.
Although.... the spell capacity should not be increased because it is already at a good amount:)
