So this is all from my understanding but with the scrapper it seems to be that you get materials based on the type of gear that you are scrapping. I.E I got more ore from scrapping plate gear and more cloth from scrapping cloth gear. Trinkets, weapons, and rings give different types of material and I don’t quite know the layout for that. Personally I would just DE everything as an enchanter. I stressed how important it is to trade with other players to get the materials needed to do all 11 warfront quest and you will obviously have more materials to create the enchantment that is necessary for the turn in to make trades with.
The Broken Isles are unique among WoW continents in that you can progress through zones in any order you want. Once you have made it through the initial quests in Legion, you are free to move about four of the new zones — Val’sharah, Azsuna, Stormheim, and Highmountain — as you wish, with enemies, quests, and rewards scaling to your level. The fifth zone, Suramar, is mostly locked away until you’ve reached a certain point in the story.
Something to keep in mind as well is that this will make enchanting materials more valuable, since it is likely most players will now simply scrap their boe greens instead of getting them disenchanted. Also redundant dungeon/raid gear can be scrapped rather than traded to the (guild) enchanter in the run. Less stuff gets disenchanted, meaning there will be less ecnhanting materials, meaning their value will rise. All the more reason to DE rather than scrap as an ecnhanter.