Heimerdinger: Change Turret Health - to Health Stacks (ward-like)

The most frustrating part of playing Heimerdinger is how fast his turrets die. A single Karthus Q is enough to destroy a turret. In teamfights they're usually getting destroyed by random AoE, without much effort.

I suggest to change the turret from a health to a pink-ward-like stack system. Given their range (450) most common midlaners could still easily outrange and destroy them. 3 / 4 / 5 hits sounds like a fair amount.