The following one-liner works for (exactly) 8 pages: pdfjam in.pdf '1,8,7,6' --angle 180 --outfile /dev/stdout | pdfjam /dev/stdin '1-4' test.pdf '2,3,4,5' --n

The following one-liner works for (exactly) 8 pages: pdfjam in.pdf '1,8,7,6' --angle 180 --outfile /dev/stdout | pdfjam /dev/stdin '1-4' test.pdf '2,3,4,5' --nup 4x2 --landscape --frame false --outfile out.pdf