Conduit bodies are nearly always a PITA ... especially if there's one at either end of the pipe!
If you MUST use one, it's best to arrange the pull so that the wire enters the box from the short side, and exits the long side. When the pull is nearly complete, a tug from the end where you first began will pull the wires in nice, straight, and tight.
However, I prefer to use a box in place of the bodies for the smaller pipe sizes, and a short piece of gutter for the larger sizes. Not only is the pull easier, the final install looks cleaner too!