Yep. Skyrim/Fallout engine is heavily single thread based, so it's basically a gimme that an intel cpu will show better performance than amd fx. Skyrim, heavily modded, only uses 1 core, maybe upto 3 with spillover, if running an enb, even lightly modded as is normal for the ps4, it'll still only use 2 cores. In fallout/skyrim a i3 2120 will hold its own vrs an OC 8350 fx.
That particular engine was used simply because it affords the broadest possible range of pc's. You can run fallout/skyrim on an old p4 if you choose to, graphics aren't really that invested,especially when put up against stuff like CoD, BF, Crysis etc