I'm old enough to have gone to high school when there was a track system. "A" track was for kids who were definitely college bound; they got advanced courses in everything. "B" track was for kids who probably would go to college - they got a solid education, but less rigorous than "A". "C" track was for kids who would probably go to work after school. They got plenty of office skills. Bookkeeping, office machines, and the like. "D" track was for those who were somewhat struggling - the girls got home management, cooking, sewing, etc., and the boys got mechanics, carpentry, etc. "E" track was for the kids (mostly boys) who were disruptive and one step out of the legal system.
It didn't have as much to do with IQ as it did with a work ethic. Some of the kids in the "E" track were much brighter than kids in the "A" track.
It also wasn't uncommon for kids to switch tracks (someone in the "A" track might decide they didn't want to work so hard and move to "B", or someone in "C" might decide to go to college after all, and move to "B")
The combination of ability and willingness to work kept the classes moving at an appropriate pace - very few were hopelessly lost, and very few were too bored to bother.
I'd love to see that system again.