Auto reordering happens if command ratings are set high. Even if one must "roll a six" to fail command check, the more times you roll, the better the chance of rolling that six. Thats if command is set at 5,4,3,2,2 if there are five levels. If there are four levels and top commander is a 4, one can expect undisordering to be much slower, but as EAW has 5, not 15 minute turns, one might expect it to be slower, in terms of number of gameturns required.