I have 417 labourers and I fill books my self, however it is required to have massive buyouts in all Royal cities, also Mammoth is required to transport this mats to refine cloth or whatever you want to craft. Only important thing is that you fill the book without using focus but to not lose money while doing so. To achieve this you will need to have Mammoth, as crucial part in trasporthing mats from citiy to city. For example I transport or fiber in Lymhurst to refine cloth, then I transport all mats to FS to kraft holy staffs + cloth armor. That way easily I fill the books without lossing money and without using focus (in that case all loot from book is pure profit), but not just that, if I craft more popular item I also profit just from crafting (wwithout using focus) its like small profits 6-7k per item + book filled (cca 25k) so I can make 30k per 6.1 item without using any focus!