Well they do, brokend down by culture-group or rather author that is:
-Eastern ones are often essay-like;
-The rest is Rough Desc with Historical background;
-The latest descriptions (of the latest Greek/Hellenistic units) are "Hail stratege" which in itself is just a form of Vanilla-style.

>_>

<_<

And no description should ever read "Hail Strategos"! Else I'd better be off again to my soap-box in which I keep my blunt axe. (If you found one such mischievous strategos, please do post below.)