electronic took navi to grand finals of a major, so they dont need to change igl. they dont need to make ANY changes.
they just need to figure out their identity as a team, and figure out how they would like to play, and build a really solid system on top of that. rosters are not built in 1-2 months, this is not 2017.
edit: a good system enables players to frag out of their mind, not the other way around. if they cant frag it just shows they are not comfortable with how they are playing, they need changes in their system or just need more time to sort out some stuff.