Key for Croatia to cover +1.5 is their def play. As long as the def does not make too many mistakes they should be able to launch some counterattacks.
Don`t think Croatia has a week team. I just want to mention some players and their clubs.
Klasnic (Werder Bremen, Bundesliga)
Prso (Glasgow Rangers, SPL)
Babic (Bayer Leverkusen, Bundesliga)
Simic (AC Milan, Serie A)
Tudor (Siena, Serie A)
Kovac (Juventus Torino, Serie A)
Simunic (Hertha BSC, Bundesliga)
The stadium will be packed with Croatian fans (many Croatians life in Germany).