Moors have rather poor eye-sight, so they are not too particular as far as light & decor goes. In ponds under bright sun-light, the fish do like to congregate in the shade, possibly to stay out of the way of predators. I never notice that in my tank, but then mine is planted, so there is lots of natural shade & hiding places. <Plus it is not nearly as bright as sunlight.> All my goldies (moors included) stay out in the open all day, only going under the plants at night when sleeping.
If you have a fairly bare tank, having some plants (fake will do just fine) or hiding places might make the fish feel more comfortable. I did notice that my goldies hide a lot more in the bare QT, even tho it is much dimmer than the main tank.