That hinge gap falls under the "no one will ever know, but I do!" category 🤔

Brass likes its natural color, so being polished then lacquered to keep it that way means anything you do that disturbs the protection will show unless you replicate it to cover your "adjustments"
Stamped hinges are inexpensive, but surprisingly square and consistent for the rate of production the stamping machines run at. Problem is any slight variation from vibration, material, dirt, etc. can cause a part to be "defective" to some extent. I'm sure it happpens a lot, but down line inspections usually catch the worst.

People gripe (especially me!) about the cost of machined hinges (milled versus stamped), but the precision is close to perfection and in many cases well worth the extra (10x +) cost.

If I was going to try and correct that gap, there are two approaches I'd consider. The easiest is to just try a replacement hinge. Measure the old and new to ensure the problem is indeed just a manufacturing error.
To fix the current hinge, only thing I can think of would be to smack the end of the leaf on a steel plate with a hammer from the back side to fuller it out in length, then file to perfection. If course this will mess up the finish and polish which probably means refinishing all the hinges so they match 😫