I don’t know if English isn’t your primary language, but you need to start adding punctuation. These punctuation lacking run on sentences do not make any sense. And you’re using quotes but I have no idea where they came from (certainly not something I said) mixed in with bullet points?
Then in what way are you “starting from the top”? In what was is this “scaling down”?
Ok. Let’s say the best players in the world, with the best gear, on a particular boss, average 100k dps on a fight that’s supposed to last 2 mins. So we’ll say 350k dps (50k for tank/healer) over 2 mins = 42M hp. So you give said boss 42M hp at M30. Tweak it a bit on the ptr (maybe due to mechanics it’s a bit high, or it’s too low) until it’s just doable in the intended 2min mark.
Now we scale down to M0 and do the same. Let’s say M0 players are expected to be doing 20k dps. So we have 70k hps (10k for tank + healer) over 2 mins = 8.4M hp. Now scale the rest of the dungeon hp modifiers.
Do the same thing for all the bosses, pulls, timers, damage done, etc… Add in a few fun positive affixes at the lower end (M0-M3 gets 4 affixes, M4-M7 gets 3 affixes, etc…) to make up for the fact lower end players will not have perfect execution like the top players, relax the timers a bit, and we’re good to go.
Sure, what I’ve suggested is a linear predicter, which tend to be inaccurate the further you predict from the original point. But because we’re predicting downwards, not upwards, were going to have a much easier time since the margin of error grows in easier content. We’ve also tested (extensively) at the top end, so we know out target is exactly where we want it to be at.
Hence you can have balanced, engaging, interesting, diverse, challenging, brutally hard content, while still having interesting affixes in the lower levels. It’s a win win for everyone. Lower end players get more diversity, higher end players get better balance/more challenge, blizzard spends FAR less time tweaking/balancing, the forums are filled with far less ‘I hate dying to random affix because of some unforseen interaction between affixes and dungeon mechanics’.