Printing multiple non-standard sized document pages on two sides of one piece of paper

Question

I am trying to find a way to create traditional Tibetan manuscripts in XeLaTex(referred to as a pecha) and one of the things I need to do is to be able to place multiple pecha pages on one sheet of paper.

I have tried to illustrate my needs in the attached image. As you might see, there are three different LaTeX environments:

1. Pecha page number 1 with the red frames. This is a title page with a small text frame for just the title.
2. Pecha page 2 and 4 are ordinary front side pages, with a big text frame.
3. Pecha page 3 and 5 are ordinary back side pages, with an even bigger text frame.

The big green numbers represent the front side of a sheet of paper (1) and the back side (2).

For the following pages 6 to the end of the manuscript, should contain three ordinary pecha pages on one sheet of paper, just like the example image without the title page and empty backside.

I am quite new to (Xe)(La)TeX and I know that there are many bad ways of doing things, so I ask for advice on how to do this properly in XeLaTeX. I need to be able to make the configuration modular enough to follow a common rule like I have explained above, but still be able to arbitrarily insert any other environments I might want to use.

Answer 1

It's not that difficult, since A4 is 21cm by 27.9cm which is precisely the right size. The document pecha.pdf was generated similar to Beginner needing help to create simple documentclass for traditional printed Tibetan manuscripts (Pecha)

\documentclass[a4paper,landscape]{article}
\usepackage{pdfpages}

\begin{document}
\includepdf[pages={1,3,5},nup=1x3,noautoscale=true]{pecha}
\includepdf[pages={6,4,2},nup=1x3,noautoscale=true]{pecha}
\end{document}

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