Why Yorick is a slightly weaker version of Nasus

Yorick's Q, next attack does increased damage and heals Yorick slightly Nasus' Q, next attack does increased damage scaling with ad and stacks, and heals for 15% damage dealt thanks to Nasus' passive

Yorick's W, a 2 hit kill wall that doesn't last very long, is often hard to land, and isn't that big Nasus' W, a point and click slow that pretty much just makes the enemy champion stop moving for a few seconds

Yorick's E, a ap scaling ability that you can toss out with a delay, not sure it scales too well with ap but it's definitely half the size of . . . Nasus' E, a ap scaling ability that you can toss out with a small delay, it scales very well with ap, and lasts even after you cast it

Yorick's R, summons the Maiden and some ghouls to attack the enemy minions or champions, but cannot command them on who to attack UNLESS you land your E, which is often difficult do to a cast range that's quite low, and a small delay The Maiden doesn't really do much instant damage causing it to often be useless in laning skirmishes, and by late game anyone can solo her if she's split pushing a lane However she can split push a lane better than a Zzrot portal

Nasus' R, get some health, do more damage, have a ap scaling aoe damage ability surround you

In this way, Yorick is just a less reliable, harder to play version of Nasus the only thing Yorick has over Nasus, are early lane skirmishes with someone LIKE Nasus, where Yorick can summon some ghouls and toss them onto the enemy, if the E hits that is . . .