I know Leipzig got money from Red Bull but the team has no star players. How do they manage to be at the 2nd place?
They've gone about setting up the club in a very smart way, investing a lot in club & scouting infrastructure, hiring some very competent people (Hasenhüttl for example is an excellent coach, did some great work with Ingolsstadt too).
Plus they got the unbeatable duo of Ilsanker (Marchisio of the Bundesliga) & Sabitzer, if those two aren't star players I don't know who are.
I don't expect them to stay in this good a form for the entirety of the season, but they could very well make CL places.