Generally, most fairway wood shafts are heavier than the driver shaft. Example would be a 65 g driver shaft, then a 70-75 gram fairway wood shaft (in both the #3 and #5). That being said, I really don’t care what the weight of the shaft is in the fairway woods as they relate to the driver shaft. Whatever works for you in weight and performance. There is no steadfast rule for progressing the weight from the driver to the fairway. That being said, I think most players will tend to go slightly heavier in the fairways. I always hate to say this because I know you want more definitive advice, but the only way to know for sure is to try it. I would add that if your goal for the fairway wood is control, then progress to the slightly heavier shaft from the driver. If you are looking for more distance out of your fairway wood and you are maybe stretching the club length out a bit on the #3 wood, you might try the lighter weight option. Personally, I have a 55g S flex driver shaft in my KE4 TC Driver and a 70 gram X flex #3 wood shaft (KE4 TC Fairway) and an 80 gram X flex Hybrid shaft in my KE4 TC #2 Hybrid. #3 and #4 irons are the KE4 FDI’s with 95g SteelFiber S flex shafts and the remainder of my irons are KBS S-Taper S flex steel at 120g. So, I definitely progress the weight in my shafts. That works for me. You might just have to experiment a little to find what gives you the performance, feel and ball flight you want.