If you truly are going to keep the same level of effort with the Unity build as you are now by spinning up a separate team then I don't see why not. With that being said though I am going to be selfish and say if there are resources available to spin up another team then I would rather those resources be spun up on new features and reworks of the existing Unity version rather than spent on a different engine. I myself have to much invested in Unity to ever look at switching and so the Unreal version would not benefit me in anyway. Would love to see a rework of the existing game server engine to move away from java to a C# mono engine with easier integrations of third party assets on the Unity store such as AI, Character Controllers, Procedural terrain generators, etc etc. Also having the game servers able to integrate with GameLift, Flexmatch, Agones, and other cloud service game offerings natively would be the bees knees.