Gnar Nerfs

Ok, so I am far from calling Gnar "balanced", having played him a lot (done well, done not so well...) I know he is in need of some... er... "adjustments". I can even agree to the fact that he needs some adjustments to prevent breaking the system with the changes to base stats in the preseason that is coming.

What I can NOT understand, is the utter demolition Riot is bringing to his base Health Regen. They MORE than halved his base regen. They did something not too dissimilar with Riven not too long ago to reinforce the idea that her shield was there to "clutchly" mitigate lane harass, which makes SOME sense, but was not well received. Gnar can't mitigate harass with a shield, the best he can do is go into Mega Gnar, and then have higher health when he goes back to Mini Gnar which, arguably, recoups some health sure. I don't see this health gain as being enough to justify a reduction of this much. (from 5 to 2.125)

Also, everything else in the notes has an annotation as to the reasoning, I'd like to know the reasoning/justification for the reduction to his base regen values. Is there something that I'm missing? Or does the health gain from going between Mega and Mini count for enough for Riot to justify this change?