If you have all the time in the world, then ergonomics is just a "nice to have" feature. As time becomes more and more critical, gun fit becomes more and more important.
Anyone with good technique should be able to shoot good slowfire groups, even with a handgun that doesn't fit. Put them on the clock and things will change.
By the way, a good fit isn't necessarily the same thing as a comfortable grip. It's possible for a gun to feel good in the hand but still not work well for a particular shooter. It's also possible for a gun that isn't especially comfortable to come up on target and be very shootable, even under stringent time constraints.
Anyone with good technique should be able to shoot good slowfire groups, even with a handgun that doesn't fit. Put them on the clock and things will change.
By the way, a good fit isn't necessarily the same thing as a comfortable grip. It's possible for a gun to feel good in the hand but still not work well for a particular shooter. It's also possible for a gun that isn't especially comfortable to come up on target and be very shootable, even under stringent time constraints.