Company A wants to hire another company to do things for them based on a contract. Company A hires company B, which is completely independent - naturally occurr

Company A wants to hire another company to do things for them based on a contract. Company A hires company B, which is completely independent - naturally occurring due to demand, to do the work. Company A is highly profitable and only has high earners in pay. Company B is barely profitable and only has lower earners in pay. How does the law have any power over this situation? You are telling me that that government would decide that an employee of another company is also your employee because they don't get paid as well as your company's average?