The thing about oil volume is where it is applied. Most sport patterns have higher total volume than house patterns. However the oil is dispersed much more evenly, meaning the volume in the middle will seem lighter than a house shot. If you tend to bowl in a hooking house they can seem very dry. I recently bowled on a 45 foot pattern second shift, and ended up playing 4th arrow with urethane. A month earlier on another house I was able to find hold area just inside 15 with a marvel pearl pn the same shift.
I am also a medium speed low rev senior, so I kind of understand what you are finding