I just started a Danish campaign and invaded Sweeden. The numbers were about equal. Sweedn had 4 Vikings, 1 spear, 1 archer, 2 Royal Knights. I had 4 Vikings, 1 spear, 2 Royal Knights. They charged over the hill and my army disappeared in front of my eyes. I counter attacked with my royals but to no avail. I left Sweeden with a new king, 40 Vikings, and 1 spear ( 1 man not 1 unit).

Next time I'll go back with a 2 to 1 advantage. If I can keep my kingdom that long.