I'm sure the oil drive is correct and trawling the internet, they back that up. After all the gear meshes with the oil pump and the basket meshes with the stater pinion too.
what doesn't add up is the # 5 slots along the shaft then it's left over a smooth shaft area and becomes loose because of it.
I wonder if the inner hub goes on first and then #5 which will take up the slack mentioned. Diagrams have been known to be wrong before!