Why do units light up?

[war is hell]

I suppose, but in any case it's hard to make any comparisons to how battles were really fought and how we fight them in EB, since the RTW battle system is simply a RTS 'version' of ancient battles.

I'm not sure about the unit officers idea either, I can't imagine that if there were unit officers for each unit, that they would have significant influence over what that unit did, apart from maybe keeping order in ranks.

I reckon these officers acting on their own initiative would only happen in the case of emergency, for example if the commander was killed or fled, or if the battle was clearly a losing one.

But anyway, part of the reason I love EB and RTW so much is because we don't fully know how battles worked or how men communicated on the battlefield (with exceptions, like Caesar's descriptions etc.), and that's why ima keep playing it

Well the RTW engine is a far cry from a realistic depiction. I know that.
Honestly I was just appealing to the historical fanaticism so prevalent on this website in order to get a quick answer. What really bothers me is the fact that the illumination effect ruins the beautiful skins that make this mod exceptional. That and the fact that i was tired of searching for a unit not in my field of view to "hold the divine light" while I zoomed in and witnessed the mayhem. Thank God for enter!

Correct me if I'm wrong but I'm fairly sure "officers acting on there own initiative" is a direct quote from Goldsworthy. It might have been Keegan or Hanson or all three. I don't feel like looking up. How accurate there deductions are is up for debate. I'm not a historian. I doubt they have any reason to make stuff up without any hint of evidence. Goldsworthy suggests that the flexibility of the manipular legion is what made it so successful.

As far as never knowing what the ancient battle field was like, that is true. We can however make deductions based on artifacts and the nature of man in general. And since he is largely the same animal now as he was back then that should give us a close estimate and we'll just have to use our imaginations to fill in the rest.

Officers in modern combat often act on there own initiative, why wouldn't they in the past? I'm not implying they blatantly disregarded direct orders or anything of sort. But if an unfortold crisis occurs(i think warfare in general contains many of them) I think everyman would do what is necessary to save his own life or the lives of his comrades. I would think that such men would have been applauded by the commander for such bravery.