I have no idea how to start researching this, so I'm going to here, where there are people who are much smarter than me. So I'm writing a story set in the medieval time period. In my story, there is a group who is consistently attacking towns in this one country. The monarch is able to get reports on the the aftermath of the attacks (reports might include approximate death count, infrastructure damage, and how much money/supplies will be lost, but these details aren't set in stone as they are the point of this question). I have a pretty good idea of long these reports would take to come in, but how detailed would they be?
Clarification: By how detailed, I'm not asking you to write my story or anything of the sort. I just need a vague sense of accuracy and what information would be included. Would there be a lot of details or not many at all? (Though I in no way believe that these reports are going to be some exact masterpieces.) Would they be able to even include a death count? How accurate would it be?
Details on Reports: These reports are created from soldiers going into attacked areas after the attackers have left. They look through the wreckage for bodies and talk to witnesses and survivors for details, but they do try to get these reports done quickly in order to get them to the monarch in a timely fashion. The reports are written and taken to the ruler by a messenger, and while I do expect some reports to go missing, let's go on the assumption that most wouldn't be.
Details on Attacks: The people attacking the cities don't attack many places at once (at most they attack three small towns a day. A big city is a large score for them). The attackers move quickly, only spending a small time at each town, so the towns generally aren't completely destroyed. The attackers' goal is to get in and get out and cause as many deaths to the town as possible. They generally aren't targeting supplies, the towns' businesses, or important locations. The most damage they do to the towns themselves is starting fires, the only purpose of which is to kill more people.
I know there is a certain extent to which it's my story and I can do what I want. But what's the high end of details that these reports can have?
(Also feel free to edit the tags, I have no idea which ones to use besides medieval)