There are pros and cons for sure. You should instead focus on the learning outcome and pick different tools for that. I have seen people use both Unity, Rpg Maker, Unreal, Stingray and other engines within the same degree or course. Even if you focus on one engine, often the students will favour the other. So rather than specifying the engine, you could allow them to pick the one they prefer themselves. One of the argument for doing level design using Unreal Engine (Unreal Editor) is that if you use the Unreal Editor you could essentially use existing assets and content to populate your level. If the students have to do everything on their own anyway, such as programming and modeling then Unity is probably better as it has less distraction. That said, both engine can do the same thing but the main difference is that Unity requires extra cost for visual scripting plugin.