Proficiency vs. Caliber Commonality for partnered LEOs

[GunFighter45ACP]

Mas,

Officer A carries 9mm & is 8-10% more accurate w/it over .40, but his/her partner, Officer B, is carrying .40. Which is a more important factor in this situation?

Thank you for your public service.

[Mas Ayoob]

No question in my mind, the confidence and competence of the officer is paramount. That's going to be important in every armed encounter, let alone every actual gunfight. Cases of officers exchanging ammunition are EXTREMELY rare in the real world.

best,
Mas