Good point, St. Pauli Girl.

I'm not a big fan of homework. As mentioned if their learning needs are being met at school, why on earth would they have to do more assigned work for 2 additional hours at home. Kind of defeats the purpose of sending them to school.
It could be that child A does the homework in 30 minutes and child B takes 2 hours to do the homework. In that case I would investigate if the program is really a good fit for child B.
Also, as St. Pauli Girl said, flexibility is key.