#why would iroh be allowed to lead this organisation with his history?

[skratchpaper]

Order of the White Lotus Headcanon

There is no such thing as a "Grand Lotus" - the title was invented purely to cater to the egos of powerful men who need to feel more special than others. The real members of the Order of the White Lotus use this title as a way to easily recognise assets* of the order that are highly volatile and need to be handled delicately. e.g. When a Grand Lotus gives an order, the order may be obeyed... or the illusion of obedience will be provided.

There may or may not be a true group of leaders in the order. But if there is, it certainly doesn't consist of former conquerors, misogynists, reigning monarchs and/or people with less than two decades of membership.

*Yes, I am saying that "the old masters" aren't actually members, they just think they are. Easiest way to prevent them from getting temperamental and trying to wipe out the order... The order may or may not have used trial and error to figure this system out.