According to the linked article, Threadripper 2 uses the equivalent of 4 Ryzen 7s, however they disable the memory busses on two of them which yields only a 2x

According to the linked article, Threadripper 2 uses the equivalent of 4 Ryzen 7s, however they disable the memory busses on two of them which yields only a 2x increase in memory bandwidth. You're correct that Threadripper tends to clock slightly lower, but the cache is on-die so it shouldn't be any different per-core than in a typical Ryzen.