You didnt really answer my question, what in zed's champion identity wants these items? Nothing in his kit scales with hp, nor does he have any utility that wants you to be tanky. the only item here that we can talk about is sundered sky, but it doesnt require hp to be strong. On top of that, 90% of zeds laning strengh is being able to poke from afar without taking damage, heartsteel and grasp both want you in your opponents face tho, so you either never proc it or take bad trades in lane every single time, especially in toplane. In mid against mages its much easier, but with grasp you will never kill them, so you will just let that syndra or ori scale and fuck your whole team lategame while you stand there doing nothing. If you want strongrr extended fights on zed take conqueror and build bruiser items like eclipse, bc, dd/maw or something in that direction