For these guys, as well trained as they are, probably not that hard. While just messing around, I shot this at USSA awhile back with a suppressed Glock in one hand and a phone in the other without suppressor sights.
Back in the day, the military was trained one handed only. The two handed grip came way after WWII. In the 70's we were trained two handed with the 1911. One day only so it wasn't much.