What’s up with this “asset-flips” nonsense thing ? Anything bought from any marketplace that has a royalty free license can be re-used by any developer on as many projects as needed. Period. It is up to the developer to use the assets wisely. Many objects as well as buildings are far from unique in the real world so why should they be in any game? Then with modular parts and ability to either change materials inside UE4 or repaint completely it is high unlikely that players/customers could notice some meshes being the same on games from various developers. Same goes for NPC characters although it would depend on the game type more. What matters the most are that main characters/objects/tools used by the players should be unique indeed because that is what they would remember the most and notice if two games used the same ones.