Of course they can. That doesn't make it wise to do so. If it for the shear joy of building another wheel as the OP states, then it might be a good thing but spokes are made of steel with a finite fatigue life. The time invested is only worth it IMHO for educational purposes. I like building wheels just once and getting gazillions of trouble free miles out of them. the relatively few dollars new parts take vs labor time two or three when people "save" money usually works out to be false economy.