Some solutions to balance tanks

First off, the largest advantage of Cinderhulk as a jungle item is how well it scales, because of the 25% bonus HP. That really should be cut down or removed, maybe increasing the flat health as compensation, unless the cost of tank stats is significantly increased. By the nature of a tank's cheap itemization path, they can rapidly become a problem for a carry, getting really tanky before an ADC can get Last Whisper, for which they have to wait until their 4th item (3rd excluding boots). This pacing is one of the real problems Cinderhulk creates, and an ADC really has no way to counter-itemize without reducing build effectiveness. They can't get Last Whisper right after their IE because then they'll have no attack speed to deal out the DPS they need to contribute in a teamfight. To solve this scaling problem, I'd suggest increasing the costs of tank itemization (very few tank items cost more than 3000g, I think Frozen Mallet is the only one AFAIK, correct me if I'm wrong). They are already gold efficient, and only get more gold efficient with the bonus health on Cinderhulk (Again, AFAIK Frozen Mallet is the only 'tank' item that costs over 3000g). While a carry's build path should still be expensive, increasing the costs on tank items would help balance the itemization race between tanks and carries. Another idea could be to increase the % resistance ignored by Last Whisper and Void Staff (40% or 45%).

If Riot is going to keep the bonus health on Cinderhulk and not change the costs of tank items, then the other three enchants (Warrior in particular) should have some scaling statistics other than CDR, because at this point, Cinderhulk by far outclasses any other jungle enchant, even Devourer IMO, in the late game. Warrior could have percentage armor penetration/reduction (working like Last Whisper), Magus could maybe have a small percentage bonus AP (5% or 10% max) or percentage magic penetration/reduction (working like Void Staff). Devourer already has its stacking mechanic, so I'm not sure it needs too much help...

This is a bit of a tangent, but the recent changes to Black Cleaver (and potential Abyssal Scepter changes) only serve to exacerbate the problem. These changes have taken away penetration items from carries, giving them fewer options to counter resistance itemization. AP carries/assassins would only have Void Staff, Liandry's Torment, and Sorceror's Shoes as practical magic penetration items if the Abyssal changes go through, while AD carries/assassins currently have only Last Whisper and Yoummu's Ghostblade as meaningful items to counter armor itemization.