An option Riot's design/balance teams should use more often.

Have more effects scale based on max. Health differences, especially around Tanks.

Max. Health size usually goes like this: Tanks > Fighters > Mages > Assassins > Marksmen. If you have the order of effectiveness on damage and crowd control scale with max Health differences, Tanks are inherently more of a threat towards Marksmen and Assassins, and Marksmen more towards Tanks, while keeping both of their strength vs the rest of the cast more in line than simply giving them % max Health damage as is.

They'd have clearer defined highs and lows than they currently do, as would most other champions.

Plus, this creates a new form of counter-building with a drawback -- buying some Health instead of those weird, stacking % damage reduction effects that spiral out of control.

Seems like a healthy option to balance the game. Just sprinkle some of it in here and there, and over time it'll do its magic.