If you're sure you won't be confused in the moment of truth, that's great. Me, I want less things to think about.
OK, here's the point. It isn't about you and me, and it isn't necessary to re invent the wheel where back up guns are concerned. A primary weapon and a back up snubbie have served many in the real world for many decades.
If carrying a semi-auto as primary and then being forced to transition to the very simple to operate small frame revolver is going to be a tactical complication, then by all means, go with what you consider to be simple.
Good grief, my man, just give it a try. At the range-- try the transistion from one firing system to another and see if it's as complicated as the problem you've created in your head.
Once you've mastered different guns, there isn't anything wrong with utilizing the system you've described. But do it because you prefer it, not because something else is too complicated.
Lastly, while the snubbie is very simple to operate, there is practice and training required to HIT with it. As Ed Lovette points out in his excellent book "Snubby Revolver: ECQ, Backup and Concealed Carry Standard" you should be a serious threat to an 8" X 11" sized target at 7 yds. I'd suggest ten to twelve yds.
Of course, before you get to that point, you need to be a serious threat with your primary farther away than that.
OK, lecture over.