Of course you may grow older because you are skilled. And the awareness that your physical condition has diminished, combined with a determination to adjust for that, can result in a defensive stance that is not greater nor lesser, but different.
I've had one hand in a cast for most of a year, and spent more than that in a wheelchair followed by a spell on crutches [never let 'em blow up the truck in which you're riding!] But I switched from my usual carry piece to one which was less likely to require reloading, and backed it up with a second gun, probably faster than a fumple-fingered reload with the broken wing.
But it's true that I'm nowadays less able to run away from a fight- so if one comes, I plan to get it over with as suddenly and noisily as I can.
Personally, I like Mr. Dean's outside carry. But I'd hedge my bets and have a sneaky along as well, I think.
"You may find me one day dead in a ditch somewhere. But by God, you'll find me in a pile of brass."
-- Trooper. M. Padgett.
The author did not say if he carried anything else...