The way I see it, the director just handed the game to the MC. If Lu Bu has an aggressive stance being NPC, he won't be willing to make alliances. The other players, in their desperation will flock to MC. Even if they won't get the top spot in the rankings, it beats getting eliminated since there's a chance of stabbing MC in the back. MC, of course, will only take in the trustworthy ones and bait out the traitors.