I think the important thing is to have the same trigger pull and action style. So, for you, multiple Glocks would be perfect.
Why? Many thousands of people who have actually gone in harms way--LE and citizens alike-- have, for many decades, carried a primary and a snubbie for their BUG. Some may prefer a small auto for theirs.
Some may simply carry two guns that are essentially two primaries. If they're the same trigger pull and action type, that's fine. Nothing wrong with it.
I know some who carry what could easily be described as two "primary" guns AND a BUG.
What's important is that you can shoot the guns you carry---not that they have the same trigger pull or action style.