Bottle Garden/Terrarium

I was given a lovely bottle garden by my daughter as a birthday present. It came with what looks like a spider plant, a peace lily and another plant that resembles lamb's lettuce. There is a gap at the front of the compost, and I was wondering if I should put a small succulent in there. I have one that needs repotting anyway.

My husband says that this is a bad idea, as succulents should be planted in sand, rather than compost, and it will die. I will add here that despite his confident opinion he knows nothing of indoor plants , so I am asking on here - is it ok to mix plants in a bottle garden, so that desert plants and 'soil plants' (as you can see, I am no expert either!) are together? It is a 'closed' one that shouldn't need watering, if that makes a difference.

Thanks in advance for any advice.