I don't think any sort of balance complaint surrounding the new runes is going to be all that meaningful, because this is an update intended to change a part of League's design, not fix its balance. There will obviously be huge balance upsets after this, along with many unforeseen abuse cases, and those will have to be dealt with in the months that will follow, but in the end the new system will be fully integrated into the game and counted as part of its balancing environment. If a champion or build happens to be OP with a specific rune setup, it will be nerfed, and if a champion ends up falling really below par, they can be buffed.
Really, if there's a more relevant conversation to be had about Runes Reforged, it's about the design of the new runes, not their balancing. Overheal, for example, is more or less just a 10% bonus to total health to any champion with sustain, and isn't going to be particularly rich with gameplay on a champion with always-on healing, i.e. any marksman. Zombie Ward might become essential for supports, as they're still required to always invest in vision whenever they can, though the gameplay it promotes is fantastic. Overcharger looks like a perfect release valve on any mage or support concerned that they're over-dipping on CDR, which is a real problem in an environment saturated with the stat. As much as I have my own reservations regarding the long-term viability of Runes Reforged, it proposes a lot of interesting effects already, some of which seem really fun, and a few of which might need another look at.
