To me, this seems to ignore the important part of how OD&D and AD&D 1st made fighter types work.
Accuracy/THAC0.
Against a foe with an AC of 2, your accuracy goes from 15% to 55% from level 1 to level 10 as a fighter; you get about +1 to hit per level, in effect.
Assuming a 17 strength (+1 to hit, +2 to damage IIRC), your attack does an average of 6.5*.2 or 1.3 DPR at level 1. By level 10 with a +2 sword your accuracy is 65% and you deal 8.5 per swing, 3/2, for 8.3 DPR; a 6.4x increase in damage rate.
By level 20 you are hitting 100% of the time, dealing 1d8+7 (11.5) on a hit with your +5 sword, and swinging 2x per round for 23 damage per round, another 2.8x the damage output.
With 16 (+2) HP you have 7.5 HP at level 1, 75 HP at level 10 and 105 HP at level 20; your DPR*HP is 10 at level 1, 623 at level 10, and 2.5k at level 20; taking the 1.5th root we get a level 10 fighter is "worth" 16 level 1 fighters and a level 20 fighter is "worth" 40 level 1 fighters in the same armor.
This was a solid alternative to later games that boosted raw damage output (swings etc); low level characters in AD&D missed a lot, and your accuracy went crazy good at high levels. A 1/4 hit rate going up to a 100% hit rate the same as a static hit rate and swinging 4x as often.