You are not a Idiot, so you are missing something. The top punches you note are for your mould. There are 2 options for this top punch. One to work with a Seaco type sizer or one to use with a Lyman 450/RCBS LAM type sizer. This top punch will not work with a Lee push thru die as they feed nose first. If you buy this top pinch it will fit the nose profile of bullets cast from this mould.Here's my mould but it shows 2 different type top punches, SAECO and Lyman, I have RCBS. Clearly I'm missing something, or I'm an idiot.
On your list in post #15 you do not need the "top punch holder" it comes as part of the "001 Push Through Size Die Body" and since you say you have a push rod they you should be set.
I just seated 160 GC nose first on a 312115 bullet thru the NOE sizer this weekend with on problems. Just be sure to lube them good even if you have already PD them.