I passed this year on my first attempt quite comfortably using schweser + CFAI EOC questions only. I don’t have a finance backrground and my work is not finance related. However, I cannot guarantee the same for everyone. It all depends on your own strength as well. But my general advice is that, focus on the big picture first (reading the CFAI text can easily make a person lose focus because of the level of details in it). Once you have mastered the core concepts, then you can start digging into more details. One more thing, start as early as you can. If you get burnt out, take a few days break to recharge. In my opinion, you can never start too early. Good luck.