The modern ballistics make differences between the 9mm and 10mm moot at best.
With some of the weak 10-mm factory loads this is somewhat true. But not so when you are using the loads like I do. No way does a 9-mm even +P+ come close to the real hot original Norma 10-mm loads like I do which are in the 41 Magnum equivalency. It is over 40% more muzzle energy and can handle 200 grain slugs. The 9-mm +P+ can just about get 500 ft.lbs but can only propel 147 grains at the most. Bullet weight has a lot to do with terminal ballistics.
“The modern ballistics make differences between the 9mm and 10mm moot at best.”
Not quite. I carry a 9mm in town, 10mm 220 grain hard cast for walks in the woods. Bullets tuned to hurt small soft bodied creatures don’t work so well on large tough creatures.