This Is How You Actually Balance Dead Man's Plate

If you want to balance then you have to look at the actual cause behind why it's so OP instead of just tuning some base stats on it. Do you want to know why people are rushing the item on every tanky champ even if it doesn't synergize that well with them? It's because the movement speed buff that it gives you is so ridiculously huge. Not because it gives you 55 armor. I guarantee you that players are still going to continue rushing this item even after its nerf.

The same thing happened with even after it was consecutively nerfed earlier in the season. People weren't buying it for the base stats. They wanted the item for its stupidly OP active (its passive was also a nice bonus too). In the tank meta when you gotta go fast, not even Sanic can dissuade people from getting these types of items. Its like the balance team doesn't learn from their prior mistakes. Don't get me wrong, as someone who likes playing bruisers and tanks, I love but I have to admit that it is currently too strong.

tl;dr Undo the nerf to the base armor and nerf its movement speed buff instead (because that's what's really OP about this item). Stop making the players do your job for you and learn how to balance these items properly. Jesus Christ.