Isn't the grip on a 10 Auto larger than that of the .40 S&W, 357 SIG, and 9 Luger? If so. the 10 Auto doesn't fit as many users. Is that not why the FBI switched from the 10 Auto Lite to the .40 S&W?
Not so much wider, but definitely longer, front to back, and the same length as Pistols chambered in .45 ACP and .38 Super. Properly designed, the difference in grip size is not that much greater, at least to me, and my hands are medium sized. People with small hands would probably have an issue with it.
The FBI switched to the .40 S&W when it was realized that it was the ballistic equivalent to the 10mm lite and the .40 S&W began to become more accepted by Law Enforcement. That it could be used in 9mm sized handguns which fit the sometimes smaller hands of Female Agents, was icing on the proverbial cake.