Non-Primary Item in Procurement Group adding an Asset

I am setting up procurement Group in 9.2.11. A basic question arises in my mind when i did one sample transaction- Can a non-primary Item in Procurement Group create Asset in AM?

I can see in Procurement Group inquiry both Primary and Non-Primary POs and Receipt. But in AM both have created separate Assets. Its strange. Please let me know if am doing something wrong.

Can some one provide the pre-requisite document and the setup document for Procurement Group setup? I have done what has been given in Peoplebooks.

One more thing i noticed, no Group seq number assigned to non-primary item.