I think it's helpful to shoot a bunch of different models when you get started to find out what you like the best.
I am kind of stuck on Glock, although I haven't decided my favorite model yet. The 17 I shoot marginally better than the 21SF, but I would have the marginally better ballistics of the 45 rather than the 9mm.
As to:
Well what if you get separated from the 1911 or whatever you spent decades training with and have to make use of a revolver instead? I'd rather have familiarity with all the common makes, models, and calibers so I'll be confident using whatever is available if things go south.
I really wonder about statements like that and how forward thinking it really is. I don't think anyone is saying don't be familiar with many makes and models, but at a point, you should just focus on one.
Why would you be seperated from your 1911? Are you bugging-out and forgot to take it with you? Is it not at your bug-in location? Do you not have enough ammo for it?
What kind of event would have to transpire to lose your 1911 but be able to find a revolver?
Anyway.... especially with a platform like a 1911, I would think it would be VERY good to focus just on it. Why? Well, your Sig's controls are different. Your Beretta's safety is opposite of the 1911. The Glock doesn't have a safety and the trigger is entirely different. Under stress, you want muscle memory to come to your aid not against you. If your muscle memory is with a 1911, you draw your Beretta acting under stress on muscle memory, and put it on safe.... well....? That's not good.
But I really think anyone who can shoot a 1911 really well shouldn't have a problem figuring out how to work a DA revolver.