My experience was that not every bulb bloomed every year and as far as I could tell, a bulb that did bloom, bloomed only once. All crinums must reach a certain bulb size before they can bloom. Since JC Harvey offsets so much, you're always going to have bulbs in the clump that are not large enough to bloom yet. But, once you start getting blooms from a clump, you'll probably have some blooms each year. Lots of crinums are scented. They are called Crinum Lily after all.
If they are getting several hours of afternoon sun, that should be plenty. Most crinums don't like to be moved and can take some time to settle in. Also, as I said above, some of your bulbs probably just aren't big enough to bloom yet. If you are going to move some of them, move the larger ones, to get blooms sooner in that area. If you can get some organic liquid fertilizer or even liquid seaweed, drench the soil with a very weak solution every couple of weeks. This will encourage bulb growth and quicker
blooms.