Yes I agree, I would divide them now as in this country you can divide in Autumn or Spring. Cut the stems and leaves down to a few inches above ground, dig up and divide before replanting some of the healthier looking corms. They may also benefit from a little general fertilizer, I would then mulch them for the winter and I'm sure you'll have a good display again next year. They are generally really resilient and will bounce back following this sort of treatment usually.
When you replant them keep in mind that they don't mind a slightly acidic soil so it might be worth mixing in some appropriate compost to the planting hole along with some grit for good drainage?
Next year when the shoots start to appear fertilize again and then make sure that you keep them well watered. Although Crocosmias like good drainage they grow in an area which is actually quite wet so enjoy a moist soil also!!...
Whenever I divide I also plant up a dozen pots as a back up but generally end up giving them away to friends!!...
Hope this helps?