Is this scenario a new legal entity (PSU, legal employer)?

Company "Company B" is a reporting unit and rolls up/is owned by "Company A" (Company A is the entity with an FEIN and already a Payroll Statutory Unit in our system)

Employees will employed by "Company A" (receives W2 from them, etc.), but for expense tracking purposes we want them to cost on the General Ledger with new "Company B" company code in order to account for those associate wages.

What is the best option to set this up in the system?

1. Set up "Company B" in the system as a new legal entity and legal employer (but not a Payroll Statutory Unit). Register them with the same tax address, FEIN, etc. as "Company A" and then global transfer the associates into "Company B".