Its a great start.The Zelda sales there were also affected due to Switch units constrains.Yes I know that the attach rate could be higher, but not everyone is a Zelda fan, and being at roughly 60% is great.
My (locked) thread about how difficulty should be a decision for the developers, not the gamers.
https://gamrconnect.vgchartz.com/thread.php?id=241866&page=1