no i think that would be bad
because then other damage needs to be adjusted again aswell which it cant because the4n anythign squishier would be fucked really hard
i think what riot can do is work with base armor and magic resist
Give champions classified as tanks high base armor, like 100+ and high base magic resist 65 or 70 or something like that
Then adjust all %pen and %shred items to only affect bonus armor
This will also help vs the whole tank assassin problem as these will then have low base defenses making them more susceptible to penetration if they do build tanky
Not optimal solution but it could patch things up a bit untill an overhaul for tanks comes along, and its an easy fix
And for a possible later fix up certain items really meant especially for tanks could provide % bonus defenses or a flkat amount + a % amount to just make them more effective on tanks. Although not all defence should be like this to provide options for non tanks ofc plenty of champs might want one or two defensive items
For example, what if thornmail would give 80 armor + 20% of base armor for a tank this would be anywhere from 100-105 armor for a squishy maybe 95 armor.