The hottest factory standard pressure Winchester .38 Special 158 gr load is 755 FPS. S&B's is 997 FPS.
With a 242 FPS of difference, factory loads are meaningless.
The heaviest 150 gr. 9mm standard pressure factory load I can find goes 1000 fps.
If you want to compare factory loads, 9mm and .38 are equal. S&Bs .357 Magnum load goes 1328 FPS at 158 gr. How is that more similar than .38 Special?
Are you just basing this on anemic factory loads designed for 50 year old Model 19s and pre-war .38s?