Definitely somewhat concerning that C9 revolves so heavily around Hai. Even though his shotcalling is unparalleled (let's be honest here, nobody in NA shotcalls as well as Hai does), Hai's performances do affect his shotcalling (and in the same token, his need to command the team puts a strain in his own performance). I can see this being a bigger issue in the world stage where Hai has to handle even stronger players than the likes of Bjergsen and Voyboy.
C9's attempt to pressure TSM into a choke at their last teamfight was theoretically a solid idea. With a heavy aoe comp and Braum's wall to section off TSM's projectiles, the teamfight could have gone so wrong for TSM. Furthermore, they probably felt that they needed to make a move before WildTurtle on Trist gets too big. Alternatively, due to the splits near that chokepoint they could also be looking to split TSM's "Protect Wildturtle" comp and pick them off one by one. However, due to Maokai being behind (he exploded rather fast), and C9 not getting there quickly enough (they were the ones trapped in the chokepoint instead and bjergsen landed a strong ori ult while Trist was free to do whatever she wanted), they got crushed instead.