My guess is that you're wrong about wow classic gold armor/resistance reduction. There were plenty of examples in vanilla of comparable skills stacking, and sometimes people exploited that. It's possible that the foundation way armor and resistance function is incorrect on personal servers, which might also account for a great deal of differences. But my guess is that each and every armor reducing capability will stack with each other. Generally in WoW Classic, similar effects piled, but the exact same ability did not (that is the reason why just one battle yell could be busy, and why you can't just spam warriors to each of sunder armor and garbage the boss).
This is something I would expect. Just Blizzard had the original data. Personal servers use server code based on which was engineered and because virtually all the rewarding world information (describe mechnaics, loot tables, expertise prices, AI, pathing, dialogue scripting, etc.) had to essentially be recreated from scratch. In many cases they did get things wrong due to incorrect knowledge or improper assumptions. In other cases things were intentionally altered like experience rates and back porting new races out of newer DLC.One of the things which I do expect they do is give us proper widescreen support. Widescreen support was clipped erroneously giving widescreen monitor users a dis-advantage by clipping off the top and bottom of the display rather than raising the FoV for the player. This was fixed by means of a 3rd party patch and afterwards patched correctly but 1.12.2 base has this issue.
I really don't wanna begin an argument , but taking into account that the way we have been enjoying classic on private servers is far different than the way classic was performed back in the afternoon, could little quality of life or balancing changes really affect tha vanilla encounter in such a bad way as people claim? I mean personal servers made up worth as well as boss mechanics and people didn't mind and could enjoy WoW Classic anyway. Can it be too crazy to say that perhaps taking advantage of some centers we have now may actually enhance gameplay and thus make vanilla more enjoyable?? I understand this is not exactly within the subject, but my biggest fear about Classic is the market won't be the same. I think people got used to create"big money" at the past few expansions and they'll purposely inflate the AH prices to get rich quicker.