Off Topic: It is not the nazie cross, but a very ancient symbol also seen in Roman mosaics. The cross that Buddha wears in his neck rotates counterclockwise, nazi cross (inspired on that) rotates clockwise.
Back on topic:
I suggest to use a external software, like 3DSMax to obtain the normal maps for the statue and then optimize the mesh to get a low poly one. Apply the normal map obtained from the high poly model to the low poly model in a material in UE4 and you will get the appearance of a very high poly using a low poly mesh. It is a classical approach for making very detailed characters as well.
Resuming. Learn about the use of normal maps. It is the solution to your problem.