Not so much, way to over engineer and over think.

A 6.0L V8 running about 500 HP and a Turbo 2.5L running about 500 HP utilize similar sized injectors. Why?.. because 500HP in either platform requires similar amounts of fuel. Yes what you were saying is correct, diff engine sizes have different efficiencies and yep, Turbo engines are usually more efficient.

However, the energy content of Gasoline is relatively standard (assuming we use the same Gasoline in both cars). So the amount of energy released in joules, or kw hours is about the same...it's how the engine gets it to the pavement that differs, and that is where your efficiencies come into play.

At a macro level though both engines require large injectors, not the exact same size because at the micro level the efficiencies are different, so are the tunes and a thousand other small things, but the end result is making large amounts of HP requires large amounts of gasoline any way you want to dress it up. Adding a turbo will not suddenly make a 500HP car get gas mileage like a 125 HP car, UNLESS you are only using 125HP. Either way that has nothing to do with the Turbo and more to do with how the driver drives the car.

You made some great points though and were pretty much spot on, just going in much deeper than needed in my opinion.