Yes Worcester have qualified as group winners and a 4 point win against Stadt will see them get a home draw as we can match them on points they will have won 5 games to our 4 but if they were to lose then we get home draw. Simples

Actually, if you read the rules in the link I posted above, number of games won does not enter into the calculation, even for teams in the same pool. For qualifiers from different pools with the same number of match points, the ranking is decided by:

(i) the best aggregate points difference from the pool stage; or

(ii) if equal, the number of tries scored in the pool stage; or

(iii) if equal, the club with the fewest number of players suspended under Disciplinary Rules in the pool stage; or

(iv) if unresolved, by drawing lots.

So, if we get a try bonus point and Worcester don't we end up on the same number of match points. We currently have an aggregate points difference of +50, Worcester are on +20. Assuming there's no wild scenario where we score 4 tries, they score 3 but somehow they manage to improve their points difference by more than 30 points plus whatever our winning margin was, then we would be ranked above them in the rankings for the QF draw.