I"ve heard strong opinions on this before. Some people rotate through an entire collection, while others consider "carry rotation" to be as good as suicide.
I train and compete with my primary gun, CZ P-07, very frequently and year-round. It's G19-sized. I've found that with the right holster (thank you JM Custom Kydex!) at the appendix position, I can conceal that sucker under surprisingly light clothing. The biggest challenge is shirts that ride up, moreso than printing. Any shirt that isn't fitted or especially thin will usually do the trick, and your "average guy" button-up checkered short sleeve shirts conceal that as well as they'd conceal a squirt gun. So that's my go-to almost always. I'm willing to dress around that rather than switch guns so I can carry under a thin T-shirt.
I also have a Walther PPS M2 that I can carry under much lighter clothing, and in a 3 Speed Holster (look them up, great products) it disappears under tucked-in dress clothing, with a spare mag! That's about the only time/reason I carry anything other than my P-07.
So my logic is: carry what you train with, and vice versa. I know people who shoot all the time with full size target pistols, and then carry snubbie revolvers that they never shoot because ammo is expensive and .357 hurts their hands.
If I'm used to shooting a Glock 19 and suddenly have to reach for a Glock 43, will I fumble it all because they're different? Maybe, probably not too bad.
If I'm used to shooting a Beretta 92 and suddenly reach for a 2" revolver? I'm guessing I'm screwed, they're nothing at all alike.
So I think having a very limited number of options to carry, and training regularly with them all, is a good compromise.
A similar manual of arms (i.e. DA/SA on both, similar sights, both semi-auto or both revolvers, etc.) would seem to help, but I'm speculating. Makes sense that if I spend 95% of my time shooting a 6 lb Glock trigger, I shouldn't be reaching for a 14 lb revolver trigger?
But "hmmmm....which gun do I feel like carrying today? My 1911 Commander or my Ruger LCP?" is probably going down the wrong path