Tell me why you think religious schools would struggle with the "lovely interplay between religion and "secular" education"?
The same way a lot of public schools struggle with the dilemma: What's the appropriate balance between religion and science within a science classroom? Is it detrimental to have an abstinence based sex-ed curriculum? Et cetera, et cetera. Regardless of the school type, issues that pertain to religion and secularism tend to be very mucky. I'm not suggesting that it's an
absolute struggle, I'm sure that there are Islamic schools that fair very well for priming students for advanced studies in secular education; it's just - in my experience - a lot don't, which can also be said of a lot of public schools, as well. America isn't exactly brimming with a plethora of great, affordable schooling options. We're doing quite well on the university level, but it's a struggle with schooling on both primary and secondary levels.