I am functionally ambidextrous with DA revolvers, so it seems perfectly sensible to have two of them, one positioned for access by each hand.
Dual-wielding is NOT the idea, here. Dual-access is. The support hand always has plenty to do, during an emergency situation,
I have carried duplicates, in the case of the Ruger SP101. The best speed-loader for an SP101 is an SP101.
I actually have four SP101 revolvers, chambered in .357 Magnum, though none are identical. Two were customized by Jack Weigand, when he was still doing custom work. Each of these two has different hammers, and, though both are spur-less, only one is DAO. I bought these as new, from a dealer that specialized in top-level firearms. The dealer ordered these directly through Jack Weigand, who had a connection either the Ruger factory, or a Ruger distributor. I bought the first one about 1997 or 1998, and the second about 2002.
My third SP101 has an intact hammer, with a spur, and one of the best factory triggers I have ever found. I wanted to be able to use a holster, with a retaining strap, in some conditions, so I added this one. I had wanted my third SP101 to have the 3-1/8” barrel, but happened to handle this absolute gem, so bought it.
My fourth has the longer 3-1/8” barrel, and I swapped its spurred hammer for a spur-less hammer, which happened to be a perfect fit. (Not all such swaps are drop-in!) I had bought the hammer as a pre-owned take-out. I bought this SP101 in or about 2006.
Two of my several GP100 revolvers are duplicates, the early, fully-lugged, 4“, stainless, adjustable sight, with the grunge grooves under the extractor. This latter feature was discontinued, when Ruger stopped caring as much. I bought my first one of these, new, about 1990 or 1991, and the second, pre-owned, some time well into this century, when I found it at a local gun shop. IIRC, I found it on their website, and recognized the serial number range, then immediately drove to buy it. This is the best version, IMHO, of one of the best revolvers in the world; how can a mere one be enough?
Notably, these are real-world working revolvers, not collectibles. I used one in a line-of-duty defensive shooting incident, and several others have been comforting, in some tense moments.