The core issue about the Kremlin balance progress is that the Balance team is tweaking the wrong parameters. Kremlin overperforms cause 2 main aspects:
1) Her main battery dispersion, while being advertised as poor at range, is mostly false than true. The vertical dispersion, the one which makes you hit or miss the target (or the critical hit spot) is the lowest of all tier 10 battleships, with only Slava beating it. To make you a numeric example, at 20km Kremlin has 97m Vdisp while Montana (the closest tech tree one) has 124m Vdisp, a 27% difference in favor of Kremlin. Meanwhile the horizontal dispersion is higher by 3m...this BAD long range dispersion isn't bad at all isn't it? Adding a 1.85 sigma (pretending a 2.7% difference from 1.9 makes a meaningful difference), shells group together at a decent rate and make it even better.
2) Her supposedly weak broadside isn't weak at all. Her citadel is the thickest at tier 10 closer to the extremities and on US level amidship. Ending the discussion here it would seem fairly weak cause above the waterline, but the citadel is also very sloped. This means, already at 10km a lot of guns struggle to pierce through it. Not to mention at higher ranges her guns can citadel a Yamato but not vice versa. Additionally, the ship sits pretty low in the water, making the broadside area not as big of a target as other ships (approx 2/3 of Yamato's broadside).
I'd add the shells penetration doesn't make sense since it's middle of the pack at close range but best in class at long range, quite the opposite of its design, but that's a "minor" flaw.
As of now, the nerfs have been:
1) Nerf to the damage output and shell ballistics.
This was a first step, not exactly the correct one but was a step.
2) 50% AA and secondary mounts hp nerf.
This one wad nothing to do with the issues, I say it's a funny one cause it literally makes no sense. Put Aux.Armaments mod.1 and this nerf is gone, the main turrets are hard nuts to crack anyway.
3) 0.05 sigma nerf.
The first time in the history of WoWs a sigma buff/nerf is so small. Still not relevant enough with the issues.
At this rate, you can nerf Kremlin for 10 more consecutive times and it will still have the same issues.
This is a change I'd like to see:
Battleship Kremlin, Tier X:
Accuracy settings tweaked to make the ship less accurate at ranges above 13km.
Model updated, now the slope of the citadel will be less pronounced.
Not a tweezers tweak on an irrelevant stat...plus, this would absolutely have 0 impact on her supposed playstyle, as you want every balance change to act.