When I last carried SP101 revolvers regularly, I had no trouble carrying one on each side, at belt level, if wearing a jacket, vest, or sufficiently-voluminous shirt. The “primary” was at 0300, because that is where I carried my duty pistol, while on the clock. My first pair of holsters were the Galco Concealable, and over time, I replaced them with PMK holsters from Milt Sparks. I also used Sparks VM II holsters, when IWB was deemed desirable, due to clothing or other considerations.
If the cover garment was deemed unable to provide enough coverage volume, the weapon at 0300 remained, but the second would move to a Kramer pocket holster, or another more-esoteric location.
While at work, in police uniform, an SP101 rode in an Alessi ankle holster. Sometimes, I would use the ankle holster during personal time, too.
When a larger weapon was felt to be needed, I could substitute a larger revolver for one of the SP101 snub-guns, or simply add a weapon to the pair of snubbies.
I should note, that due to the thinness of my medium-sized fingers, I can get a full firing grip on an SP101, and with my youger eyes, in those days, I could shoot an SP101 about as well as my duty Glock, so I did not feel handicapped by the smaller weapons. I up-gunned, as perceived necessary, with larger revovers, which I could, and still can, shoot better than a Glock.
In 2004, I switched from G22 duty pistols, to a P229R. In 2006, I worked non-railed P229 pistols into my personal-time carry, which ended several years of carrying multiple revolvers during personal time, but I continued to regularly tote a back-up snub-gun, either SP101 or S&W J-snub.
I retired from LEO-ing earlier this year. I do not always carry two guns, these days, but it is not unusual. I am back to carrying mostly revolvers, with “primary” being as large as an GP100 or S&W Model 327 PC, and the usual second gun being as small as an Airlite J-snub. It remains to be seen whether I revert to carrying a pair of SP101 revolvers, as I need to do some ammo testing, to settle upon a modern load that takes advantage of their recoil-damping mass, while not battering my aging hands and wrists too much. A shoulder/arm injury has interfered with that ammo testing. Getting old is not for sissies!