Did a dry fit to try to work it out for myself. Don’t remember the ‘extra’ hole at the bottom of the triangle bracket, but this is the only way it goes together that makes sense. View attachment 1715750656
Have a look at the schematic you posted for the saginaw pump post # 1.
That triangular bracket is for the power steering pump, not the alternator . The triangular bracket for the alternator has two holes that are used to attach the bracket to the water pump. The Alternator attaches to the other hole in the bracket.
I think you are confusing the two triangular brackets.