Both of you don't know because no one knows how this will play out. They've both been great enough that I can see them beating the stuffing out of each other. I don't know how big of a size difference there is between them but Fedor is a small HW while Silva is a big MW.
Fedor's power is unquestioned and his takedown attacks are amazing. That hand trap into a huge looping hook transitioning into a double underhook take down. I'd put my money on Fedor. I know Silva is elusive and won't be easy to touch but Fedor knows how to make distance and bait Silva and then close distance. He's been the little guy in the HW division killing giants for a decade by close the gap.