If those Singaporeans here in the US are excelling, their scores are not showing up on the NAEP or the internationl tests.
Meeting or excelling at an exemplary curriculum is something else entirely.
Of course Singaporeans don't show up on the comparative tests, Asians of all varieties - including utter failures like Hmong with a 3% college graduation rate - make up less than 4% of US high school students.
They and other successful students are statistically buried by the millions of hip-hop culture types who can barely read.