I've had a different experience with Crinums (both Moorei and Powellii) here in Corfu, and am just about giving up on them. Despite shamefully frequent watering, the leaves are never abundant or beautiful and it's the grayish scaly stalks that one sees since the leaves are clustered at the top. The flowers are no more beautiful that the Lilia or Amaryllises that thrive here on no care at all and no summer water. In the 7 years that I've had them neither bulb has increased significantly in size or produced more flowers.
In contrast the Agapanthus leaves are plentiful and beautiful all year round and keep multiplying. I think, Fleur, Attica might be too dry for them. I know they love the humid air here.
Incidentally, and for what it is worth, on two different visits to La Moratalla, I never for a moment doubted that the "ground cover" was anything other than Agapanthi, with therir characteristic rounded ends. The crinum leaves come to a point and the whole plant rises from the ground....