I absolutely agree. I think even with the addition of formations, a moveable roster would have at least two uses in organizing your fighting company:
1) organizing your troops on the roster by battlefield role: e.g., keep your sword-masters, your archers, and your shield wall together in their categories to make juggling weapons and armor between them a little faster and easier.
2) organizing your troops by rank (possibly within battlefield role categories): e.g., you loot some sweet new armor and give it to your favorite dude. You’ve conveniently lined up your brothers based on their level/how much you like them, so figuring out who gets the top dog’s hand-me-downs and who, in turn, gets that brother’s hand-me-downs (and so on) is no longer a nightmare requiring you to jump around the entire roster comparing stats and attributes.