StarCraft 2 is is basically entirely dependent on single thread performance so the 8700K will always be faster than any currently available Ryzen CPU at SC2.
Jim from AdoredTV complained about the use of SC2 in CPU benchmarks in his Benchmarks - what to trust video since it only serves to test IPC and single thread performance which is why Intel CPUs continue to be the best CPUs for SC2.
Sorry Brantyn but that is not exactly true. There are some games that are VERY CPU intensive, Starcraft 2 being one of them. It is the game I play the most and I can tell you that from experience. I think it also has some coding problems that add to the problem but in any case the CPU is much more important. The GTX 760 that I have can easily max it out and have no performance issues at all in 1v1 with my 4570 (non-K). However, in 3v3s and 4v4s, with maxed armies, I get terrible FPS drops during battles.
Short Answer: SC2s Engine isnt optimized for MultiCore-Performance and uses a maximum of 2 Threads. So basically it does not matter if you own a 2000$ Server CPU or a 100$ DualCore if they have the same single Thread Performance. In the past, Intels CPUs were superior in SingleThread Performance, and thus were the best Choice for most Games which didnt utilize 8+ Cores. Now AMD didnt only catch up, but took the lead in single thread performance as well. All whilst maintaining a much lower power usage and depending on what amount of cores you choose for much fewer bucks.