The only way to copy what Poly and City do is to copy their students. For years we've seen superintendents and education wonks come in vowing to bring the success of magnet schools to the rest of the system.
Unfortunately, they're squeezing the balloon at the wrong end. In effect what you see is a loosening of rigor and accountability at magnet schools to bring parity— not a raising up of neighborhood schools.
One of the motivators of success for students at a magnet school is the fear of getting a one-way ticket to your zoned school if you fail to uphold your end of the educational bargain. I know it was for me when I attended Poly. When I taught at Douglass I saw lots of kids who ended up there because they didn't cut it at a magnet school (often because of poor choices rather than academic performance) and they expressed that regret.
Certainly better management of money and resources will help, but there's still a question of raw materials: the capability of a student.
There are students I taught with massive developmental deficits— emotionally and intellectually. Schools like Poly and City simply can't meet these students' needs and deliver the level of advanced education we expect.
The argument that we can is a dangerous alchemy, perpetuated by politicians and advocates with little idea of how a classroom works.