thank you very much suemc 9 I think you are correct :)

A light deprived croton? They are more colorful when given enough light https://en.wikipedia.org/wiki/Codiaeum_variegatum

Looks like an etiolated Aglaonema "Black Cherry".

"If it's not broke, don't fix it." Your plant is obviously happy and doing well. I wouldn't separate them, they make more of a statement together as one. Although, I would rotate the pot from time to time, so that each gets its moment in the sunshine, so to speak. Aglaonemas don't mind having their roots disturbed from being repotted. Since the pot is only half full, it wouldn't hurt to check and see if it is rootbound. Rather than pot up, I would just do a full repot instead. This would also raise your plant up much higher in that pot and allow more light to reach the lower leaves. For my plants, I like using a fast-draining mix, such as the Miracle Gro Cactus, Palm, & Citrus soil. And I would also mix it with equal parts of some Miracle Gro Orchid Potting Mix as well. The orchid bark would keep the soil from becoming too compacted and would let the roots breathe in the fresh air they need to stay nice and healthy. Way to grow! :)