Clones need less intense light when rooting, and is probably the reason they're housed under fluorescents. Less heat and less light keeps transpiration down, and keeps clone mortality down as well. Mothers will grow just fine under fluoros, but they'll probably grow a bit more vigorously under more intense Halide lighting. But, if you're not trying to pump out clones every couple of weeks, fluorescents will continue to veg your mothers out just fine.