Japanese players struggle to make quick decisions at the individual level. Let me repeat: at the individual level, before even considering teamwork. Honestly, it's a cultural issue.
It's not something coaching can fix. No matter how much a coach orders them to go and just die, they just don't do it. That's why they collapse every time in high-leverage situations.
Who they need isn't Zellsis to boost their courage. They need someone who will take responsibility and keep leading the game even when they get shot and die. An igl who with strong charisma, issues forceful, one-sided commands. He must force players to do something even if they don't want to.
Regardless of how they exchange opinions and feedback during coaching sessions, the team must become one with an absolute command and obedience system during the game. No brainer, just shoot following to the shotcalling. That's when optimal efficiency will be achieved.
At first, I thought japanese igls like art or others labeled toxic could do that. They absolutely couldn't.
They need someone like Munchkin the Shogun.
On the coaching side, Coaches have to let them do what they want. Meaning slow play. Every attempt to impose an aggressive playstyle on Japanese teams has failed. They can't become PRX anyway. So old Zeta always remain Japan's ideal team though.
I don't think xqq is that bad of a coach. He's not particularly strategically brilliant, but he knows his players' good and bad sides. Carlao prepared counterstrats and setups better than expected, but tried to impose a playstyle that didn't fit. The result was a team aggressive until rounds 7-8, then just as useless as ever, doing nothing until the last 10 seconds.