You don't have to be too meticulous on your block order. However, I always suggest placing the rad before your lineup of blocks, but after the pump. For me, it's Pump>Rad>CPU>Chipset>Res.
And also, in relation to the discussion of high flow systems with multiple blocks...
It's for many blocks under one pump. In order to keep the flow and not strain the pump, they use a bypasser line. I don't really approve of this and would rather buy a more powerful pump, or set up another loop.