The only way you're going to get a .38 Special or 9mm to meet or exceed the ballistics of a .357 Magnum are to either cherry pick the most powerful .38 Special and 9mm Boutique loadings against the mildest .357 Magnum loadings or to compare the 9mm and .38 from long barrels against the .357 Magnum from short barrels
@ which point, I'm going to go back to my original post....
Which is after all what the OP had brought up - shooting a .357 out of a snub..
I fail to see any significant difference between a 124 gr 9mm out of a Browning Hi Power or any 125 gr . 357 out of a 3" or less snub.
I've also commented before on this.
BBTI does a wonderful job - kudos to Jim for that.
W/out publishing hi - low - extreme spread and standard deviation figures, the data is simply too rough to make any meaningful determination out of.
.357 loads of any weight quite often have a swing of 200 fps from hi to low for 5 shot strings.