I actually thought until recently that "everyone did it that way" for aircraft and tank models. I always did in my Enamel days, anyway.
With Flat Acrylics, it is a snap, airbrush on the paint, clean out the airbrush, use airbrush again for anything not needing a mask, repeat, repeat, with longer pauses for colors that need a low tack mask.
Clear coat after the final paint color, and let the whole mess sit overnight,,,then decal, and clearcoat again.
If you use the same clears as the paint brand, it is fast and easy,,,,,I use Aeromaster and Polly Scale clears now, I like it better than Pledge with Future. (or add one extra day for each coat of Alclad Aqueous)
Rex