Succulents do not need saucers. That's counterproductive.
These two plants that I circled:
...are suffering from etoliation. They need stronger light and for longer periods than they have gotten for at least several weeks. The one on the right is suffering more than the one on the left.
I can't tell much about the others, but remember that your grafted cacti are temporary decorations, not real houseplants that you can cultivate year after year. The reason you have so rarely seen a tall grafted cactus like this is because they almost invariably die. They're gimmicks that the big box stores sell.