Triple Carbs are very common on straight sixes, such as those found on Datsun L series motors. No problems with one throat per cylinder, although you have to make sure that each carb is balanced first, and that the opening of the throttles are synchronized. Otherwise you get poor off idle performance and a shaky motor in low rpms.
For the 2.4 litre six cylinders, carb throat sizes in the range of 40-45mm were used depending on how how the motor was built.
I built several engines running DCOE webers, and they work well, but were rather finicky. They didn’t play so nicely with modern fuels, and requires a systematic approach to tuning them as there are idle jets, main jets, emulsion tubes and air correctors that all have a theoretical impact somewhere in the power band. They would require a balance tube for things like the vacuum advance, but otherwise it wasn’t necessary for a smooth running engine.
On the Dodge sixes with the shared intake ports, three single barrel side drafts like Moose has would work well. Maybe improvements could be made on the intake manifold to shorten the length of the runners, depending on available space.
I don’t know if it has been mentioned yet, but six cylinders sound GREAT with individual carbs. Adds at least 20hp to the butt dyno.
Anyway, I spent a lot of time tuning triple carbs and so I can ramble about them enough to bore most people...