Not all set is the same either. Assume you are starting with a natural straight board. Some bows can take 2" of set and still have pretty good early draw weight while another bow may feel mushy. All you can really do is work the bow to full draw weight and read the signs the bow is telling you as you progress. If it starts taking set early in the process the wood is either wet or you are asking too much. If the set is only in certain places then the tiller is not even. If you only have a litte set right near the handle it can translate to 4" at the tips.
Tim Baker mantra: Wide enough near the handle to take no set, wide enough mid limb to take little set. ( something like that)