The line is blurred. If a game feels nothing like the period its set in, then it's not enjoyable. If the game is so detailed that it requires a lot of pre-setup army organisation, or the detail slows the game's progress, or it requires ANY in game roster keeping / paperwork, that doesn't work for me either - and I don't much care how historically accurate it makes the game.
I, and the gamers I play with, all know their history to a greater or lesser extent, and all have been gamers for many years. For games rules, we want something with a bit of tension, decision points a plenty, something that plays with a bit of pace and lastly, give a bit of period feel. Most importantly, they should not be mentally challenging / tiring.
Two or three times a year I meet up with the League of Gentleman Wargamers for one of our weekend bashes. It's an illustrious bunch of authors and gamers: name dropping a bit, some of the best known LOGW regular attendees are Charles Grant, Angus Konstam, Kevin Calder, Bill Gaskin and Chris Henry, amongst other less well known gamers (includes me). When this group meets there are generally between 12 and 16 players and the rules we play are always at the 'simple end' of the spectrum. I would say, to a man, we are there for the fun of the game rather than to try and recreate something that could be called a 'simulation'. To a man, I guess, we just like playing with toy soldiers.
Here's a pic of a little LOGW Dresden 1813 game. Played on 3, then 4, 16 x 6 tables, over two days, with 12000 figures, the entire rule book for this game was written on four sides of A4. Indeed, several of these rule sets are in evidence in these pics - and not a single roster (other than the umpires arrival list) was used for the entire weekend. Obviously, a slightly larger game than that envisaged by the original post - but, the rules worked and it felt Napoleonic. Units were all the same size, roughly, by frontage - the number of heads in the frontage being somewhat irrelevant as units simply had an 'integrity factor'.
I suppose, what I'm trying to illustrate is that detail isn't always for the better. At the end of the day, if the game was easy to play and fun it was good, if it was hard work or dull it wasn't.