The Tories have already shat it on a no confidence vote in the govt. It is now a personal vote on Humza.
Parties don't like leaders of opposite parties shocker. Maybe there be a string of votes in the confidence of Ross, Sarwar, Harvie and Rennie and see what the numbers are like.
It would be a complete farce if the smaller parties could topple the leader of the scottish parliament on their whim since the system was designed to represent the diverse views of scotland and therefore unlikely there would be a majority.