Yup, it will work. This time of the year, Crassulas, like Aeoniums are actively growing. Just lay the leaf on top of the soil, it will make either some new leaves or some new roots first. But keep the leaf cutting in a part shade area till you see the new growth. Part shade too, if a stem with roots, till it seems firmly anchored after a gentle tug. Just keep media moderately moist on first planting, and the hardest part...leave them alone.
Once you see the new growth and the other one has rooted too, then you can bring it out, in a partially protected area.
