The future as I see it is that coding will become a relatively trivial skill. The economists would each know how to code and that would remove you from the equation. They would implement whatever thing they were trying to do themselves.
This would scale to support any number of economists. This would also be a simpler model and that simplicity might lead to a better product. In your model, the economists must explain to you, then you must write the code. That adds a layer where errors could happen - you misunderstand the economists or they explain poorly or you forget or whatever. If the economists could implement things themselves - less room for "telephone" type errors. This would also allow the economists to prototype, experiment, and iterate faster.