because yoricks whole theme was being a summoner, who brings his little army to run a lane down
but old Maiden leaving him without his command while he got jumped by a bunch of people made no sense
also yorick can choose to make his maiden run it down a lane while he leaves her to do other things by recasting R while shes summoned
the AI actually sucks btw the only way to stop it from fighting is for the yorick player to run away really far and the only way to make it target someone is to land your e on your target, where as ivern can just press R to control daisy and who it hits
once again its like comparing apples to oranges= bruiser split pusher to support jungler