RE: HoW many Decoys?
I'd be careful setting dekes behind you. It's a good idea, but it may not be safe. You should be able to keep an eye on your dekes in case some nut job comes stalking your dekes. Having them behind you may leave the opportunity for them to get behind you without you knowing. If I was to set up like this, I'd make real sure the tree I was against was wider than my shoulders....