Grievous Wounds Imbalance

I feel that there's quite a few champs now that have large health pools and large healing ability. Of course, the usual response is "itemize against them," but that's really only two options, and they are not viable to many champions, not to mention grossly imbalanced. First we got Executioners, at a super low 800g to get. Absolutely great for ADCs and all. But it's only build option is into an item with what many believe to be a better anti-tank tool. Also, they get it on every auto attack, no questions asked. Now, compare that to 2900 to just get access to grievous wounds for magic damage champions. On top of that, it only procs if the enemy is below 35% health, meaning you have to actually get that healing enemy low enough for it to start affecting them. How is this at all balanced? A smart Swain won't let himself get that low for it to proc, so the idea of using it to stop/stem his healing is moot. Why do the casters that have to work to hit their spells have MORE limitaitons on their ability to stop healing than the champs that can just click on an enemy to stop it?

And on top of all that, there's another glaring hole for Grievous Wounds: manaless AP champs. Or at least champs that don't need to build mana but need to stop a healing opponent. The new kit is pretty decent, but he still gets destroyed by enemies that have healing that can contend with him. If Vlad's top facing a , , or any other champ with good healing, his only option is an item that is mostly useless since he doesn't use mana. Same can be said for a variety of tanky tops that don't focus on mana and have to try to wear out a healing opponent.

I'm not sure about the full implications of doing so, but it seems like there should be a health based Grievous Wounds item, or at least something to give more consistent healing reduction against all those top champs that just sit in lane for an eternity and you can't do anything about their healing.