My thoughts on Yorick
He was supposed to be a "minionmancer" or sorts, with his damage focusing on his ability to summon and (sort-of) command lost souls to do his bidding.
Honestly he was closer to this pre-rework, except with his damage focused on the summoning of minons instead of the minions themselves. Right now is sort of the same issue, most of the damage he has is loaded into his Q with his minions contributing about as much as they did pre-rework, while still dying to just about any damage thanks to the tiny amount of hp they gain, especially late game.
The maiden has a substancial impact to a fight (as well as split pushing) but the maiden herself doesn't do much other than give YORICK the ability to do bonus damage.
The minions still die instantly, their damage is ok, if a BIT low. I think if they recieved more hp and a tiny bit more damage they would be fine maybe 25-30% of Yorick's max HP instead of 15%, or perhaps more base hp as well as a bit more base damage (maybe 12-105), and the damage on Yorick's Q getting nerfed he would probably be a bit better off.
Or perhaps something like "While within X units of the Maiden of the Mist, Yoric's Ghouls have increased attack speed, movement speed, and their HP is doubled as well as focusing on the Maiden's target." instead of the 5% max hp thing
Still nerf Yorick's Q scaling though, hitting 600's with just a bruiser item and triforce is a bit much with the low cd it has.