Right now I have great confidence in G. Skill supplying the best chips. They quietly stopped manufacturing of the 3600C15 1.35v bin just before the 5000 series Neo RAM was announced. I am more than certain they are simply using these chips in the Neo since they can charge a premium for them. The 3600C15 bin is close to the best chips made.
Still it's very hard to state what speeds RAM will do when overclocked. For example if you were to buy another set of 8Pack sticks you might not be able to reach the same timings or maybe you can get away with lower voltage. Tom's Hardware did a review of the G. Skill 2x16GB C16 bin and they reached 13-14-14-35 at 1.45v:
https://www.tomshardware.com/uk/reviews/gskill-trident-z-neo-ddr4-3600-c16-2x16gb-review
It's not beyond the realm of imagination to expect an increase to 1.5v would allow +200 Mhz and something like 14-14-15. That kit could be snapped up for £219 recently and addition of a temperature sensor was an added bonus.
Thinking about it I wouldn't be surprised if the whole G. Skill 5000 series is the exact same chips just with voltage changes in place to reach the required spec.
Still when talking about RAM of this spec they are all probably very close (within 5%) of each other regardless if you go for G. Skill or TeamGroup offering. Just get what is readily available and in stock.