You may be right. I was hoping for it to be an option for early sustain though. Maybe it would be better to have a T1 version that heals a flat amount per orb, and a T2 it builds into that heals a % per orb.
Problem is, then flat healing would either suck for higher base HP heroes, and a GODSEND to lower base HP heroes; as well, units with high fire rate can EASILY utilize this especially if they kill a guardian or walker and, well, now you have a full-heal for free. Could add an interesting rushdown style to laning, though I do feel like it's a 'use or die' type item, where there's not really any point in NOT using it.
Instead... maybe not health, but health regen?
[Lich's Finger] - Passive VITALITY, 500 cost.
-2 Health Regen
+5% Bullet Lifesteal
+5% Spirit Lifesteal
PASSIVE
On Securing or Denying a Soul, gain a short buff to all healing.
[+10% Bullet Lifesteal, +10% Spirit Lifesteal, +7 Health Regen] [Lasts 5 seconds.]
This would instead offset the healing onto health regen and lifesteal itself, making it GREAT for picking off individual souls but also not making it a powerplay for rushing down guardians and walkers.
Probably just my take on it though, could be anything else though.