Cause that's a full sized Warband... which would make you a warlord... not a simple raptor champion. The main reason I didn't allow anything like that is largely because it makes you FAR more powerful than Arabar from the get go... it kinda raises the question of why your following him rather than the other way around. 
The main reason I didn't want anything like that is for characters to grow... and to make things more desperate. After all, if Crixus has access and leadership of a 46,000 strong army why would we need to steal from the night lords? I understand the wish to be powerful but... we are kinda suppose to be just beginning a pilgrimage of the previously unfaithful. 46,000 troops kinda... well ruins the whole plot... which is pretty flexible if I do say so myself with plenty of room for events you guys suggest. But as I have said, 46,000 troops makes Arabar, and his flock completely obsolete... also he has told no one the name of the new warband, including his inner circle (you guys) and was gonna reveal it after the barge was secured and on its way to the eye