Or maybe their actual playtests determined something different from the community's theorycraft. Remember, they obviously didn't playtest 3rd that well, because monks were "obviously" overpowered.
A lot of lessons *should* have been learned from 3e playtesting and weren't. 3e was the first try at "professional" game design. Making mistakes is forgivable. Not learning from them isn't.
I have no idea what you're trying to get at. 4th Edition is the first edition in which magic items are accurately and transparently factored into the power curve.
NPCs and PCs scale slightly differently in 4e, resulting in about a -1/7 levels on d20 rolls power lag for PCs in combat.
And this conclusion is based on actually playing the game 1-30 in a real campaign? Or just theorycraft?
Everquest created theorycrafting (seriously, at least in the english-speaking market EQ was the first game with a large enough math-fluent on-line community to develop the tools needed to reverse engineer game mechanics and find the neato bits). WoW polished theorycrafting. Designers ignore theorycrafting at their peril, because despite theorycrafting being a derogatory term, competent theorycrafters (say the char-ops folks) are damn good at their job and the system IS the math.
Better hit the Wayback Machine and let Gygax know that his concept of hit points is inappropriate for the fantasy genre.
4e and previous editions handle injury differently from a mechanical PoV. The schizophrenic attempts to "quantify" ("excuse the existence of"?) what hp mean don't interest me. Mechanically, previous editions fit the fantasy genre better than 4e, which in turn fits the superhero genre *perfectly*.
Or maybe your theorycraft is meaningless in the face of actual play.
Twin Attacks>Careful Strike. Full stop. Skill challenges are broken mechanically. Full stop. Astral Storm>Meteor Swarm. Full stop. The fact that Combat Challenge goes from inflicting perhaps 1/5 of the targets hp at lvl 1 to about 1/20th at lvl 30 is indicative of bad/non-existent playtesting: at upper levels, Elites/Solos should just IGNORE the fighter's CC because the damage it inflicts is laughable.