The manual page order defines a pattern that is used to consume all pages in the PDF. For this case all you need it to specify the entries as Page 1, Increment 1
For the 2 page PDF specify 6 entries
For the 3 page PDF specify 4 entries
For the 4 page PDF specify 3 entries
For the 6 page PDF specify 2 entries
That should do it.
Within the Imposition component under the Layout tab you can choose manual for the page order. Here you can add a page and an increment. I find this difficult to figure out. I am trying to set up some layouts for Business Cards and am having a rough go of it. I would like to have a variety of layouts that correspond to how many pages are in the PDF. So if the PDF contains 2 pgs it will fit 6 up each of the 2 or if the PDF contains 3 pgs it will fit 4 up each of the 3 and so on. I would like a clear explaination of how the manual page ordering works.