Lower YG armor pen to 10 and/or make Maw have the same arpen passive as DB.

If you lower it to 10 from 20, the the 2 items only give 20 total, not 30. Or make the passives the same but just different values, still adding up to 20 max. Before you go gutting the champions, please consider it is actually the items which break actually balanced champions.

EX: Jhin is balanced. His high damage is at a cost of static attack speed, a 4 shot reload system, and low mobility if he has not hit a crit. He is meant to scale crit/attack speed/damage. But because arpen is so easily acquired currently, he can forgo the intended build for arpen and deal greater damage for the majority of the early-mid game where he normally would be just coming online. I can get 19 flat arpen from runes alone. That on top of the 2 item 30 makes most champions defenseless for the majority of the game. If I add Maw, that is another 10 for a grand total of 59 arpen at 3 items, which btw are all useful and appropriate on an ADC. Add in Mortal reminder for the arpen passive and healing reduction and tanks are never an issue.