If an employer-employee cooperate to commit a crime, both are responsible

Sure, if they’re both aware of and complicit in committing the crime. But in most cases, the employee is unaware of the crime, or commits it under duress. If the employer orders the employee to commit the crime as part of their job, the employer should take the larger (if not total) share of the consequences due to the power dynamic.

A huge part of prosecuting a crime is establishing motive, and duress should move most, if not all, of the guilt onto the employer.