Unfortunately, I don't think it's possible to make UE4 match the other shaders by any reasonable means.I think marmoset has a UE4 shader, but it's wildly inaccurate anyway.But to get it to look good inside UE4, I think you need to reduce the contrast in the roughness map. Bring everything closer to a middle range.
unchecking srgb of the roughness map sometimes helps me bring UE4 look similar to Substance viewport. There's an Advanced Lighting map that comes with Started Content in UE4. Worth a try.
This is my first time working with ue4 and my metal surfaces look terrible compared to sp and marmoset how it is supposed to look. Marmoset and ue4 are both only using 3 spotlights in the same place to get similar lighting.