Seriously, out of all the jobs out there...ALCHEMISTS CANT attach materia? You are saying that the mythical job of turning things into gold and finding the secret of eternal life cannot attach a piece of rock to another material item?
Why? O.o
In all honesty I would EXPECT alchemists to be the Disciple of the Hand with the best success rate when it comes to fuse two already existing items into a single more potent one.