If managing a lot of resources in native code is bothersome, then you might want to consider using a blueprint base. You don’t have to use blueprint for anything beyond exposing some properties to edit and use those in C++ as normal. Then you can create a blueprint in the editor and just assign asset references through the content browser. This is a “Data-only Blueprint”.
Don’t worry about the performance from loading from a blueprint either, in cooked builds, both native and blueprinted classes are serialized from the Class Default Object in the same way.
Edit: Oh, I just noticed you do randomization in the constructor. This probably won’t do what you want, because the CDO gets randomized once, then every other object created will copy itself from it. A good middle ground would be to load the asset references in the constructor, and randomize and apply as usual where you first had it.