I combine some of my succulents together, but usually of the same type, like different kinds of Aeonium together, or maybe different types of cacti together. Though I am slowly adding and mixing in different types together that I know have similar dormancy times. It saves me the frustration of potential overwatering. But there are just some types that are happier on their own container, a singular beauty of its own.
I guess you can put your croton together with an Hoya, but just know first if that Hoya is the type that likes more water or the type that likes to dry out a bit. My hoyas are potted separately, have noticed that these three I have shows different preferences with their watering, media and lighting needs.
