I have spent a total of 3 years in the Falklands, between 1983 and 2002, and was collocated with the various Army units every time. It was not uncommon to have soldiers who could neither read nor write. In 1983 we used to do pay parades and some soldiers made their mark with a thumb print.
By far the best educated, and behaved, I served with were the Ghurkhas.