Originally Posted by
Belmorn
Blood of sargaras which is a huge component in the crafting cycle is BOP , which means you will need to obtain them with the crafting character of choice.
Therefore, double gatherer wont be effective at all.
In most cases this means you would have to run dungeons / do world quests / raiding with those toons which you realisticly wont be able to do on all 8 chars you suggest.
Until bloods become BOE its probably better to focus on one or two chars as they will be a lot more powerfull due to artifact traits and having to travel around the whole continent with 8 chars gets rather time consuming.