[2019] Suggestion to ease the HE spammy ships

Why?

No, i get why we get a proposal for overheating Barrels (aka nerf Des Moines - because she had this problem).
But what I don't understand is why armor should be uniform for all ships in a tier.

So, yeah, to keep consictency with the game each configuration in the system you propose should be checked and recalculated, which effectively means creating dozens of new ships.
And then balancing them. So I very much doubt that such system will work in this game.

If a ship had a defined armor in history - we try not to change it, and some creativeness is done only in special cases, like in module boundaries or in hull plating lowest threshold for a tier.
Why is it always russian bias?
German battleshipsships had increased deck armore for years (FdG is still the champion, i think), Even Lyon with 30mm plate is immune for 6-inch-without-ifhe-fire.

And when ships are being balanced - all their weak and strong points are taken into account, and into tech tree composition.
Why is Atlanta a premium, if she has been built, and Dallas and Seattle wasn't? Because she's an outlier, playing her properly requires different playstyle from the regular lines, which has to be learned.
And making all ships exactly the same destroys one of the biggest features of the game, so I doubt such a proposal can get into a base game. And special modes don't have tier matcmaking anyway.
So, sorry, but what you're proposing is essentialy making an another game.

If you're talking about my personal opinion - I just don't like playing T10's because it's boring.
But your picture here is inaccurate - there isn't such a difference in power between tiers, which is precisely the reason you can be uptiered and still be best in your team.