im not so sure i agree with the above statement as there are a lot of synths that use shards from both your breakdown of craftsmanship and magic craftsmanship, biggest example being any of the dyed cloth.

Since no one really knows for certain, i try to keep both high and about even. though drinking an odd juice or so with magic craftsmanship while doing dyed cloths several ranks above me seems to help (though it could all just be in my head)