My 1973 20in gunned battleship works well

Amazingly enough (to me), my 20in-gunned battleship from about 1973 works well in Springsharp. My designation is GB/BB/1927. At first, I did not read the specification closely enough. I just reduced the armour to match the original specification:

GB/BB/1927   935ft x 125ft     8-20in/45
             16in Belt        16-6in/50
              6in Deck         6-4in AA
             27 knots

The hull is flush-decked with a raked bow and overhanging stern (cruiser spoon). The main armament is in two quadruple turrets forward with wide spacing between the barbettes. The 6in guns are in twin turrets aft of the main turrets. The AA armament is just the 6-4in guns in shields on the first level above the forecastle. This is the Springsharp report:

GB/BB/1927 1973 version, Great Britain Battleship laid down 1927

Displacement:
 70,182 t light; 73,479 t standard; 79,200 t normal; 83,777 t full load

Dimensions: Length overall / water x beam x draught
 941.66 ft / 935.00 ft x 125.00 ft x 35.50 ft (normal load)
 287.02 m / 284.99 m x 38.10 m  x 10.82 m

Armament:
      8 - 20.00" / 508 mm guns (2x4 guns), 4,000.00lbs / 1,814.37kg shells, 1927 Model
   Breech loading guns in turrets (on barbettes)
   on centreline, all forward, 1 raised mount - superfiring
      16 - 6.00" / 152 mm guns (8x2 guns), 108.00lbs / 48.99kg shells, 1927 Model
   Quick firing guns in turrets (on barbettes)
   on side, evenly spread
      6 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1927 Model
   Anti-aircraft guns in deck mounts with hoists
   on side, evenly spread, all raised mounts
 Weight of broadside 33,920 lbs / 15,386 kg
 Shells per gun, main battery: 90

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 16.0" / 406 mm 530.00 ft / 161.54 m 20.00 ft / 6.10 m
 Ends: 16.0" / 406 mm   16.00 ft / 4.88 m 16.00 ft / 4.88 m
   389.00 ft / 118.57 m Unarmoured ends
   Main Belt covers 87 % of normal length

   - Torpedo Bulkhead:
  8.00" / 203 mm 530.00 ft / 161.54 m 35.00 ft / 10.67 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 16.0" / 406 mm 10.0" / 254 mm  16.0" / 406 mm
 2nd: 6.00" / 152 mm 6.00" / 152 mm  6.00" / 152 mm

   - Armour deck: 6.00" / 152 mm, Conning tower: 16.00" / 406 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 146,834 shp / 109,538 Kw = 27.00 kts
 Range 12,000nm at 15.00 kts
 Bunker at max displacement = 10,298 tons

Complement:
 2,359 - 3,068

Cost:
 £24.243 million / $96.973 million

Distribution of weights at normal displacement:
 Armament: 4,240 tons, 5.4 %
 Armour: 29,452 tons, 37.2 %
    - Belts: 7,679 tons, 9.7 %
    - Torpedo bulkhead: 5,491 tons, 6.9 %
    - Armament: 5,543 tons, 7.0 %
    - Armour Deck: 10,104 tons, 12.8 %
    - Conning Tower: 636 tons, 0.8 %
 Machinery: 4,635 tons, 5.9 %
 Hull, fittings & equipment: 31,856 tons, 40.2 %
 Fuel, ammunition & stores: 9,018 tons, 11.4 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   137,674 lbs / 62,448 Kg = 34.4 x 20.0 " / 508 mm shells or 29.6 torpedoes
 Stability (Unstable if below 1.00): 1.12
 Metacentric height 8.7 ft / 2.7 m
 Roll period: 17.8 seconds
 Steadiness - As gun platform (Average = 50 %): 83 %
   - Recoil effect (Restricted arc if above 1.00): 0.95
 Seaboat quality  (Average = 1.00): 1.66

Hull form characteristics:
 Hull has a flush deck
 Block coefficient: 0.668
 Length to Beam Ratio: 7.48 : 1
 'Natural speed' for length: 30.58 kts
 Power going to wave formation at top speed: 44 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 4.00 degrees
 Stern overhang: 4.00 ft / 1.22 m
 Freeboard (% = measuring location as a percentage of overall length):
    - Stem:  38.00 ft / 11.58 m
    - Forecastle (20 %): 29.00 ft / 8.84 m
    - Mid (50 %):  29.00 ft / 8.84 m
    - Quarterdeck (15 %): 29.00 ft / 8.84 m
    - Stern:  29.00 ft / 8.84 m
    - Average freeboard: 29.72 ft / 9.06 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 70.9 %
  - Above water (accommodation/working, high = better): 213.1 %
 Waterplane Area: 91,025 Square feet or 8,456 Square metres
 Displacement factor (Displacement / loading): 109 %
 Structure weight / hull surface area: 254 lbs/sq ft or 1,239 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.43
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is excellent
 Room for accommodation and workspaces is excellent
 Ship has slow, easy roll, a good, steady gun platform
 Excellent seaboat, comfortable, can fire her guns in the heaviest weather