I am of the opinion I should know how most popular firearms operate, be it a revolver, semi-auto, or even black powder.
I agree having a common platform is likely better, but stuff happens. You might lose your gun, get robbed, get damaged beyond repair, come across a dead MZB who has a non-Glock semi-auto (are you just going to leave it there if it is of the same caliber?).
As for concealability, will it be necessary if SHTF, and everyone carries openly, like the old west? It is currently at freezing outside where I live. Going concealed means under at least one or even more layers. Open carry might be the better option.