If Son Heung-min's leadership were truly an issue, as people claim in online communities

Even at Tottenham, which is a multi-ethnic and multi-national collective, there would have been issues regarding Son Heung-min if that were the case.
Even Richarlison and Romero, who are actually called troublemakers, haven't caused any issues under Son, and thanks to his good image locally, he is a player who can even beat Mane in fan votes.
Is Son Heung-min not a great captain? That could be true.
But he is definitely not a bad captain as some people claim.
If you watch European football, a player like Son is an A-grade captain.