Is drupal able to handle the following usecase?

Hello,

I am currently evaluating whether Drupal is the right platform to build an employee assessment portal on.
This is the use case I am trying to solve:
The company that wants to use the portal is quite large and has many locations in various countries.
Employess of the company will be assessed throughout the year (using quizzes and other means), to ensure they comply with federal guidlines.
The quizzes are managed by a compliance department at a location X in country Y. The employees are managed by a HR department at a location X in country Y.
It is important that neither an individual from the compliance / HR department has any access to the results of employees at any other location or country.
There is a country manager that will have access to all results belonging to the corresponding country and will be able to run reports.

The company has aquired multiple other companies, so it is important that there are for lack of a better term 'subsites' hosting the same content with a different look and feel due to the difference in branding of the aquired companies.
To make it clear, I don't want to have a replicated drupal installation, but one single system serving all these needs.

I realize that this is little information, an eloquent guess is good enough for me at this point.

Thanks + Regards,

Steve