Firstly, I would be hesitant to label these developers 'scatterbrained' because you simply can not follow their thought pattern. I am likely to place blame with

Firstly, I would be hesitant to label these developers 'scatterbrained' because you simply can not follow their thought pattern. I am likely to place blame with you if you can not understand the value in tangential tasks. This shouldn't really be an issue anyway because you should be in a position to veto efforts you deem unnecessary. Secondly, I see a bunch of people suggesting you micromanage these people and I must advise you that nothing good can come from this. You need speak with and make your self available to people daily or several times a day but you MUST give them space to accomplish something on their own. Thirdly, you must set expectations and required outcomes. You can only set expectations if you know the clear path from A to Z and if that isn't the case, you need to trust your employees when deadlines slip. You need to manage the expectations of your customers so that there is a wide buffer between when you expect employees to get it done, and when you expect to deliver to your customers. Your inefficient employees aren't dumb. They know their peers are outperforming them. It is your job to provide a safe stable work environment where employees can relax when there is a lul, and strive for greatness when there is a deadline. You can not work your employees to death.