I dont see a reason why you couldnt, as long as they are not crowded on the upside and you still have the roots somewhat cozy in the pot. However unless it is an exact same clone i wouldn't as you could run the risk of mixing up your tags. Another problem would be introducing a virus or pest from one to the other. I have many duplicates and many divisions of the same plant and they all get potted up on there own. I also do not reuse old bark or water for the same reason above.
To each is there own if they are healthy pest/disease free plants of the same exact clone id say sure go for it.