Well panic, they've been used in that configuration for over 60 years on all engines from the Stovebolt's on up.....I guess the many thousands of people that have used them successfully in this manner all those years obviously knew something that you don't. It was common for the guys running Flathead's with 3 x 2's to also use a dummy carb or block off the center one because it was overcarbed, and its no different than the Offy intakes for the Stovebolt or 194-292 engines available today that run the same 3 x 1 carbs on them, either progressive or 1:1 if they choose.