Yes, it's possible. For each battle arena, you need two objects: AdvMapDesc and AdventureFlybyScene. The first is the arena itself with decorations, and the second is a pointer to the grid position on the battlefield, which refers to the AdvMapDesc, as well as some minor details. Then, you need to add the AdventureFlybyScene to the list of duel arenas.

Dear RedHeavenHero, could you please provide more details, if it's not too much trouble:
1) As I understand it, the arena itself with decorations needs to be created in the map editor. What size should it be (tiny, small, or does it not matter?)
2) What size should the battle space be?
3) How do I mark it out?
These are at least the questions I can ask right now because I don't quite understand the subject, but I really want to. I saw a mod by Zenithale that adds a lot of new arenas, but I couldn't find a working link to it. I downloaded another mod and tried to figure it out, but I didn't understand much.
4) Could you please tell me where these duel arenas are located in the TOE game so that I can look at all the necessary files and try to understand them?