A 35 knot British light cruiser for 1921

I was hoping that a British light cruiser for 1921 that could make 35 knots might not have to be so large, but this one is over 10,000 tons standard. The armament is 9-6in/50 QF guns, 6-4.7in AA guns, and 12-21in TT. The armour belt is 3in and the deck is 2in. I suppose that having the underwater protection like this is what makes the design have to be large:

GB/CL/1921, Great Britain Light Cruiser laid down 1921 (Engine 1941)

Displacement:
 10,248 t light; 10,605 t standard; 11,409 t normal; 12,053 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
 (640.08 ft / 636.00 ft) x 62.00 ft x (19.00 / 19.81 ft)
 (195.10 m / 193.85 m) x 18.90 m  x (5.79 / 6.04 m)

Armament:
      9 - 6.00" / 152 mm 50.0 cal guns - 114.33lbs / 51.86kg shells, 150 per gun
   Quick firing guns in turret on barbette mounts, 1921 Model
   3 x Triple mounts on centreline ends, evenly spread
      6 - 4.70" / 119 mm 45.0 cal guns - 52.35lbs / 23.75kg shells, 150 per gun
   Anti-air guns in deck and hoist mounts, 1921 Model
   6 x Single mounts on sides, aft deck forward
  6 raised mounts
      Weight of broadside 1,343 lbs / 609 kg
      12 - 21.0" / 533 mm, 22.00 ft / 6.71 m torpedoes - 1.425 t each, 17.102 t total
 In 4 sets of deck mounted side rotating tubes

Armour:
   - Belts:  Width (max) Length (avg)  Height (avg)
 Main: 3.00" / 76 mm 415.00 ft / 126.49 m 16.00 ft / 4.88 m
 Ends: Unarmoured
   Main Belt covers 100 % of normal length
   Main belt does not fully cover magazines and engineering spaces

   - Torpedo Bulkhead:
  0.70" / 18 mm 415.00 ft / 126.49 m 19.00 ft / 5.79 m

   - Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
 Main: 4.00" / 102 mm 3.00" / 76 mm  4.00" / 102 mm

   - Armoured deck - multiple decks: 2.00" / 51 mm For and Aft decks
 Forecastle: 2.00" / 51 mm  Quarter deck: 2.00" / 51 mm

   - Conning towers: Forward 4.00" / 102 mm,  Aft 0.00" / 0 mm

Machinery:
 Oil fired boilers, steam turbines, 
 Geared drive, 4 shafts, 120,149 shp / 89,631 Kw = 35.00 kts
 Range 5,200nm at 16.00 kts
 Bunker at max displacement = 1,448 tons

Complement:
 551 - 717

Cost:
 £2.396 million / $9.584 million

Distribution of weights at normal displacement:
 Armament: 363 tons, 3.2 %
    - Guns: 346 tons, 3.0 %
    - Torpedoes: 17 tons, 0.1 %
 Armour: 2,373 tons, 20.8 %
    - Belts: 818 tons, 7.2 %
    - Torpedo bulkhead: 204 tons, 1.8 %
    - Armament: 273 tons, 2.4 %
    - Armour Deck: 1,035 tons, 9.1 %
    - Conning Tower: 44 tons, 0.4 %
 Machinery: 3,175 tons, 27.8 %
 Hull, fittings & equipment: 4,336 tons, 38.0 %
 Fuel, ammunition & stores: 1,162 tons, 10.2 %
 Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
 Survivability (Non-critical penetrating hits needed to sink ship):
   14,633 lbs / 6,637 Kg = 135.5 x 6.0 " / 152 mm shells or 2.0 torpedoes
 Stability (Unstable if below 1.00): 1.19
 Metacentric height 3.4 ft / 1.0 m
 Roll period: 14.2 seconds
 Steadiness - As gun platform (Average = 50 %): 52 %
   - Recoil effect (Restricted arc if above 1.00): 0.30
 Seaboat quality  (Average = 1.00): 1.04

Hull form characteristics:
 Hull has rise forward of midbreak,
   a normal bow and small transom stern
 Block coefficient (normal/deep): 0.533 / 0.540
 Length to Beam Ratio: 10.26 : 1
 'Natural speed' for length: 26.97 kts
 Power going to wave formation at top speed: 59 %
 Trim (Max stability = 0, Max steadiness = 100): 50
 Bow angle (Positive = bow angles forward): 8.00 degrees
 Stern overhang: 0.00 ft / 0.00 m
 Freeboard (% = length of deck as a percentage of waterline length):
    Fore end,  Aft end
    - Forecastle: 20.00 %,  29.00 ft / 8.84 m,  27.00 ft / 8.23 m
    - Forward deck: 15.00 %,  27.00 ft / 8.23 m,  27.00 ft / 8.23 m
    - Aft deck: 50.00 %,  19.00 ft / 5.79 m,  19.00 ft / 5.79 m
    - Quarter deck: 15.00 %,  19.00 ft / 5.79 m,  19.00 ft / 5.79 m
    - Average freeboard:  21.96 ft / 6.69 m

Ship space, strength and comments:
 Space - Hull below water (magazines/engines, low = better): 150.3 %
  - Above water (accommodation/working, high = better): 196.5 %
 Waterplane Area: 27,746 Square feet or 2,578 Square metres
 Displacement factor (Displacement / loading): 114 %
 Structure weight / hull surface area: 102 lbs/sq ft or 499 Kg/sq metre
 Hull strength (Relative):
  - Cross-sectional: 0.96
  - Longitudinal: 1.32
  - Overall: 1.00
 Hull space for machinery, storage, compartmentation is cramped
 Room for accommodation and workspaces is excellent