Maybe I'm misunderstanding your point here (and I don't really want to drag this argument on even further so no worries either way), but if you're saying that the 247 composite rankings would theoretically only have 95 players that end up with a top 100 ranking, that's not how it works. They just average together number ratings (or whatever, I don't really care enough to have researched how they do it) and then sort by that new rating number so you still end up with 100 guys in the top 100 at the end of the day. But you're correct that if one service ranks a guy 400th while the others rank him 50th, it's going to drag him down a lot and that's kinda the point of it.
If I recall correctly, one limitation of this is that one or some of the recruiting services used to not bother ranking Canadian prospects, so they would always be dragged down in the 247 composite as a result. I feel like this is something that was discussed with Guerrier and Brissett.