Currently, we have most of the bestiary taken up with 'Enemy Within' threats and 'Denizens of the Imperium' - which I think are pretty essential to the game. We also have 'Enemies Without' and 'Enemies Beyond' which I am more concerned by.
In the 'Enemies Without' only the Eldar are included (no Orks, Genestealers or anything else). I am not sure why this is, but it's curiously limited and I cannot see many Dark Heresy games actually inspired by Eldar threats to be honest. Certainly no more so than any other species. We also have quite a limited size of bestiary for the chaos demon threats, which I'd suggest is a pretty big part of the game.
For me, if space is limited, I'd prefer to remove the Eldar stats and beef out the Chaos information. Eldar can be held back for a separate supplement, along with Orks, Tyranids and the rest or simply given more emphasis in Dark Heresy's sister games (Rogue Trader, Deathwatch, etc).
Dark Heresy is essentially a game about conspiracies in human societies - which is a rich enough background - so why not keep the Xenos totally out of the corebook apart from vague references to mysterious alien threats that normal people will rarely experience?
Edited by EchoEcho