Roman numerals are simple. However, they take a little more thinking when reading or writing them. In fact, a whole new level of numeracy is required to use them. I as in 1, II as in 2, IIV as in 3, IV as in 4, V as in 5, VI as in 6 etc. X for 10, L as in 50, C as in 100 M, D an in 500 and M as in 1000. But when you have a number like 45682 which becomes MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMDCLXXXII
it gets quite impractical as M is the highest number. Even a year like MCMLXXXIV for 1984 is long to write.
As for printing pages of a document in Acrobat which is encoded/numbered with roman numerals, the document must be saved or modified with a program that will wipe the page numbering scheme. Pages in the print dialog will return to the default format of 1, 2, 3 etc.
I use PDFill Free Tools. I merge two documents together and the page numbers in the print dialog are back to normal.