No I don't think so. After AOR, they will go through the sponsor's documents and let you know if anything is missing. After that's all done and you have SA, they will send it to your respective visa office and look at the person to be sponsored's documents. The bulk of the application isn't even looked at until after SA. I have never heard of them just returning an application that is missing some stuff. From what I have seen, they contact you and ask for you to send in the missing pieces. I'd have them ready to go if I were you, because eventually they will ask for them.