According to my firearms instructor (who teaches LEO's) that one has to practice something 12 times in order to remember it in short-term memory... and practice soemthing 3,000 times (if I remember the number) for long-term memory.
Many departments use firearms with manual safety's, but they practice and practice.... and other departments don't practice and their officers only shoot once a year per the state qualification test (how scary)!!!
Doesn't matter if one is a LEO or just a private citizen, it is all about practice and shooting skills... and not just at paper targets and in a low-stress envirnment... but any practice is better than none.
I personally have and use 1 handgun... and my only comment is... "be careful of the guy with one gun, becuase he probably knows hows to use it... and use it well."
My wife's gun is a sub-compact version of mine.. so no matter which firearm she or I grab from either nightstand, in the middle of the night or where ever we may be... they both operate the same (more for her safety due to her shooting less than me).
Remember... practice makes perfect and knowing and understanding each and every firearm you own and use is key... and if you don't, never be afraid to ask for help from someone.