There are those who think a 1776 needs 48 IDAs. There are those who put a single progressive on a 2332. None of this is a black-art, there are formulas for sizing pretty much anything once a set of values are established.
The thing is... having a "2276" doesn't tell you very much. There are no shortage of guys willing to throw a stroker crank and some 94s in an otherwise super-mild engine and sell it at a price-point. Displacement is only one variable in making power.
Think of it like this (at least for now): an engine is an air pump. The more air that gets moved through the pump, the more power it's going to make. The displacement of the pump has an effect on capacity. But if you are trying to move air through a straw, you'll move a lot less than through a 3/4" pipe, no matter how much swept area is in the cylinders.
Everybody will tell you that the power is in the heads-- because the heads determine how much (and how efficiently) air gets moved. The cam and the heads are interrelated, because the cam controls how long and how much the valves are open. This matters at least as much as the swept capacity of an engine.
Your builder has an idea what he wants to use for heads and a cam. If these parts are mild, he's specing 40s because generally, smaller carbs offer more drivability than big ones. If the engine doesn't need 45s (because of the heads and cam), then putting them on won't help, and will probably hurt.
... or maybe he's an idiot. That's the thing about this hobby-- there's no shortage of thieves and charlatans who prey on guys who know just enough to be really dangerous. Assuming you have a guy who is trustworthy, most VW engine guys fall into 2 camps: drag racers and octogenarian guys who rebuild 1300 cc single-ports. They are going to have different recommendations for sure. Neither are going to build the engine you want, unless they are really listening to you.
If they are listening, and you trust them, then the best advice comes from Jim Kelly. Unless you're ready to assume 100% responsibility for how the entire thing turns out, you've got to pick a guy, and go with what he thinks.
Above all, disabuse yourself of any notion that you can choose more wisely and frugally than most other people, and end up with 10 lbs in in your sack when you paid for 5. In this hobby, you might not always get what you pay for, but you'll always pay for what you get.
Always.