It may not be the exact same process but it may produce the same outcome. Protecting the vapor barrier around the meat.
Now, all things being equal at the start of the cook for all briskets, fat to lean tissue ratio, % of moisture in the meat, total weight. Any change in any of these and results will vary, maybe to a great degree.
O #1 - When cooking BBQ, I want the vapor barrier there as long as possible because I think this leads to a product with greater moisteure content when finished. At some point introduing foil to protect the brisket from loosing it's vapor barrier "too soon" works well. The more meat you have in your smoker the less likely it is that you will need foil to accomplih this. Cooking 250*
O #2 - This vapor barrier cannot be replaced by a pan or water sitting in the smoker.
O #3 - Any water vapor produced by a water pan will likely move right on out of the cooker along with the smoke and any water vapor produced by combustion of the fuel. I don't see it hanging around inside the cooker. The Vapor around the food is different.
O #4 - The time is takes for meat in a full smoker to dry out will be longer than the same smoker with one brisket in it. Even though a smoker full of meat may show a rebound temp time of only 40 minutes longer that one with one brisket in it, the smoker is still under load. It has a somewhat reduced airflow especially around the meat and has to work harder to maintain the temps while the meat is still cooler than the temp in the cooking chamber.
So, I think that foiling brisket can replicate a full smoker better than some other methods. I actually beleive tha unwaxed butcher paper is much better than foil in this regard as it protects the vapor barrier and lets some moisture out in the process.