Yeah, this season isn't very good for this region teams. Zvezda lost to obviously weaker team on paper, while Dinamo Zagreb haven't managed to beat similar level opponent. Money probably isn't main problem this time because they haven't lost against big teams with huge budgets. I think one of the main reasons of such results is weak local leagues. Team like Crvena Zvezda or Dinamo Zagreb have just 1-2 powerful opponents in their leagues, while rest of time they have to play against parked bus in general. After this they aren't ready to play different style footbal in Champions league.
This is the main reason. Money plays a role, but it' is not the major one. Teams from our region have to prepare for EU competitions almost separately. Bjelica did that with Dinamo last few years , where Dinamo had very "normal" results in the domestic league because they were playing EU tactics in those matches to prepare for EU competitions. He never adjusted to opponent and insisted on the same tactics to prepare the team and ingrain that style into players so they are ready for EU football.
You can watch Osijek now, he will do the same thing with them. I know I sound like a fanboy, but Bjelica was the reason for good results of Dinamo, major one.
