I don't know about you but in combat shooting pratice I don't thumb cock hey my 340 PD has a non exposed hammer couldn't thumb cock it if I wanted . BTW it is made with out a transfeer bar also they say. No hammer exposed to get hit no need really makes a nice trigger pull .
I too have a Centenial Model S&W ( no Hammer J Frame)
But if your firearm of choice needed to cock the hammer each time I bet you would get pretty good at setting that hammer.
Also the Cow Boy action shooting as well as the IDPA, and Steel shoots help with mind set and mussle memory.
The movement to Draw and get the sights on a target when your brain says NOW! Either by the buzzer or the visual threat.
The confidence that you can hit targets. The knowledge to shoot again if you miss or shoot until the target falls. Already having faced some stress of the timer can only help if the real thing happens. That is why the Army runs around shooting at each other in training. Learing how you died may keep you alive in real combat.
And if that takes the form of dressing up like Wyatt Earp, The Lone Ranger, Or Marshall Dillon and sling lead the old way who cares. Draw, Sight picture and Press are universal. Be you Paladin, Barney Fife, or Tommy tactical. If you can not get the gun out, align the sights and squeeze the trigger to hit what you are aiming at, carrying a gun or fifty will not matter.
The idea in Cowboy Action, that when one gun goes dry and you simply grab the next should apeal to you.being a proponet of two or more guns and being able to transition from Rifle to shotgun to handgun should make you happy, old west Three gun.
Now one of the biggest fads in CAS is the Wild bunch that use Pump shotguns and 1911's that are Single action but you don't have to cock them each time.