I think Union Berlin actually needs to get strikers on the team. Because in the last season union, Berlin was actually unable to score enough goals. But they defended decently because they conceded the same amount of goals as Bayern Munich. So I think they will need to score more and also play attacking football. Getting attackers, at least better attackers is going to make them more fearless.
Dont know if they are already looking for an Striker but they have a few very good players that have scored many Goals in the season and also international.
And if they can get Robin Gosens that would be getting them an always dangerous forward on the left side and also a player that is good on defending.
Specialy on the left side he can for sure bring some very good reinforcement to the Team.