The only team that I could see match blow for blow with FNATIC is Paper Rex but their W-Key Gameplay gets easily shutdown by the structured + insane raw aim of the FNATIC players.
Either EDG or PRX. Those teams are mechanically ahead of pretty much everyone except FNC and while a lot of people say PRX just runs it down, they do have strategic depth. EDG has pretty good strategic depth and you can say that Giants made EDG seem not as strong as many anticipated, that game was also a hard antistrat.
Unless Buzz completely turns it up for DRX or EG players play career level games and are on top, its hard to say. I think any of those teams mentioned here have a chance.