Crop rotation is done for several reasons. Different types of vegetable require different levels of nutrients, for example brassica which need a lot of nitrogen follow peas and beans, which leave the soil enriched with nitrogen etc. The second consideration is to prevent pest build-up. The third consideration is what you want to grow and what your family want to eat and how this fits into the different crop rotation areas.
If you grow crops that don't exactly fit into a scheme, because they stay in over winter or stay in the ground only for a short time with room for a follow-on crop you will invariably have to compromise. I would put the sprouting broccoli in this year's brassica bed, because it is not in for long next year, but growing for most of this year. It is less obvious with spring cabbage, because that is not in for long enough this year or the next. So invariably compromises will need to be made. It is never a perfect system. In my garden anyway. Just remember that brassica are heavy feeders, as are squashes for example, so any follow-on crop will benefit from some feeding.
A helpful leaflet explaining crop rotation:
http://www.gardenorganic.org.uk/schools_organic_network/leaflets/CropRotation.pdf
