Do not despair , good fellow Sir of the Apple. ;-)
What you see are just the shortcuts crossover puts in your Mac Program folder.
The actual program data incl. the modules folder are on the virtual "c: drive" that crossover stores in a special folder. In that folder you will find the usual windoze folder structure and can navigate to the Mount & Blade program files.
Depends on your settings, but usually Crossover uses
/Users/YourUserName/Library/Application Support/ Crossover/bottles/YourBottleName/drive_c/
BTW you want to check the Crossover Compatibility Database - M&B Warband is not entirely supported, as far as I remember there were a few minor hickups... It was playable though.