Are there any prerequisites for the course, like basic programming skills?
If not, I would definitely go with UE4. Using C# with unity is pretty straightforward for a programmer, but for students not used to that way of thinking blueprints is way easier to grasp. And as you said, over all UE is more artist friendly.
My main argument would be this:
The course is targeted at all students. The more technically inclined will have no problem with either software, but it will make a big difference for those leaning towards art. To start with many of them will have a difficult time grasping even the basics of text based scripting and would need a dedicated programming course to stand chance. Second, the better art tools in UE4 will give them a chance to excell in areas where the “programmers” might struggle.
In conclusion, no matter what you choose techies will probably have an easier time. But by choosing UE4 you are significantly leveling the playing field. As for future job prospects, they will need to be prepared to switch to another engine, for example one of the in house engines used by the large publishers.