Riot should "tweak" champions every patch along with larger nerfs/buffs
If you tweaked a champion every single patch, you'd have it balanced after a couple patches.
Example scenario:
clearing jungle too fast and rushes damage item for freelo ganks
-5 armor level 1 and increase scaling armor
Not going to be horrendously shit after that, not going to be broken (if the example was a buff)
Do THIS several times instead of "hur durr increase lethality scaling by 20% and add a bunch of cheap items that give 65AD and flat armor pen" "oh shit it's busted"
): 56+91-50
Total 97 armor left.