Several basking branches and spots is always a good idea when you have multiple dragons in a cage. Sometimes the more dominant ones will take the best branches and spots and leave less dominant dragons to find somewhere else to bask.. and if they don't have anywhere.. that can lead to problems.
The other post was correct, dominant dragons can and will nip and bite each other.. especially if there is not enough food. Sometimes it happens, sometimes it doesn't. If there is only one pair in the cage your chances are much less likely for them to nip, but there is always the chance one will.. doesn't even have to be dominant or aggressive.. could see the tail or toe as a food source and go after it.
However, i'm not sure exactly what you are talking about.. but if you are talking about the two dragons laying on top of each other.. this is most likely not a dominance issue.
Young dragons are very social and they will interact with each other and lay on each other all over the place. I keep groups together when they are young and have seen this time and time again.. one dragon will be laying down and another will lay on it, and another will lay on that one.. and so on and so on.
Here's a pic to illustrate my point. These were all fine and never nipped.. just liked to hangout and be together. Five minutes later the one on the bottom would be on top..they just like to perch on anything they can find. lol

brandon
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Dragons by Nature